Humanized antibodies

ABSTRACT

The present disclosure provides humanized antibodies, including antibodies comprising an ultralong CDR3 (e.g. bovine) and uses thereof.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/584,680 filed Jan. 9, 2012, which is incorporated by reference hereinin its entirety.

FIELD

The present disclosure relates to humanized antibodies, includingantibodies comprising an ultralong CDR3.

BACKGROUND

Antibodies are natural proteins that the vertebrate immune system formsin response to foreign substances (antigens), primarily for defenseagainst infection. For over a century, antibodies have been induced inanimals under artificial conditions and harvested for use in therapy ordiagnosis of disease conditions, or for biological research. Eachindividual antibody producing cell produces a single type of antibodywith a chemically defined composition, however, antibodies obtaineddirectly from animal serum in response to antigen inoculation actuallycomprise an ensemble of non-identical molecules (e.g., polyclonalantibodies) made from an ensemble of individual antibody producingcells.

Some bovine antibodies have unusually long VH CDR3 sequences compared toother vertebrates. For example, about 10% of IgM contains “ultralong”CDR3 sequences, which can be up to 61 amino acids long. These unusualCDR3s often have multiple cysteines. Functional VH genes form through aprocess called V(D)J recombination, wherein the D-region encodes asignificant proportion of CDR3. A unique D-region encoding an ultralongsequence has been identified in cattle. Ultralong CDR3s are partiallyencoded in the cattle genome, and provide a unique characteristic oftheir antibody repertoire in comparison to humans. Kaushik et al. (U.S.Pat. Nos. 6,740,747 and 7,196,185) disclose several bovine germlineD-gene sequences unique to cattle stated to be useful as probes and abovine VDJ cassette stated to be useful as a vaccine vector.

SUMMARY

The present disclosure provides humanized antibodies, includingantibodies comprising an ultralong CDR3, methods of making same, anduses thereof.

The present disclosure provides a humanized antibody or binding fragmentthereof comprising an ultralong CDR3.

In some embodiments, the humanized antibody or binding fragment thereofcomprises one or more human variable region framework sequences.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 is 35 amino acids in length or longer,40 amino acids in length or longer, 45 amino acids in length or longer,50 amino acids in length or longer, 55 amino acids in length or longer,or 60 amino acids in length or longer.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 is 35 amino acids in length or longer.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises 3 or more cysteine residues, 4or more cysteine residues, 5 or more cysteine residues, 6 or morecysteine residues, 7 or more cysteine residues, 8 or more cysteineresidues, 9 or more cysteine residues, 10 or more cysteine residues, 11or more cysteine residues, or 12 or more cysteine residues.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises 3 or more cysteine residues.

In some embodiments of each or any of the above or below mentionedembodiments, the antibodies or binding fragments thereof comprise acysteine motif.

In some embodiments of each or any of the above or below mentionedembodiments, the cysteine motif is selected from the group consistingof:

(SEQ ID NO: 41) CX₁₀CX₅CX₅CXCX₇C, (SEQ ID NO: 42) CX₁₀CX₆CX₅CXCX₁₅C,(SEQ ID NO: 43) CX₁₁CXCX₅C,  (SEQ ID NO: 44) CX₁₁CX₅CX₅CXCX₇C,(SEQ ID NO: 45) CX₁₀CX₆CX₅CXCX₁₃C,  (SEQ ID NO: 46) CX₁₀CX₅CXCX₄CX₈C,(SEQ ID NO: 47) CX₁₀CX₆CX₆CXCX₇C,  (SEQ ID NO: 48) CX₁₀CX₄CX₇CXCX₈C,(SEQ ID NO: 49) CX₁₀CX₄CX₇CXCX₇C,  (SEQ ID NO: 50) CX₁₃CX₈CX₈C,(SEQ ID NO: 51) CX₁₀CX₆CX₅CXCX₇C,  (SEQ ID NO: 52) CX₁₀CX₅CX₅C,(SEQ ID NO: 53) CX₁₀CX₅CX₆CXCX₇C, (SEQ ID NO: 54) CX₁₀CX₆CX₅CX₇CX₈C,(SEQ ID NO: 55) CX₉CX₇CX₅CXCX₇C,  (SEQ ID NO: 56) CX₁₀CX₆CX₅CXCX₈C,(SEQ ID NO: 57) CX₁₀CXCX₄CX₅CX₁₁C,  (SEQ ID NO: 58)CX₇CX₃CX₆CX₅CXCX₅CX₁₀C, (SEQ ID NO: 59) CX₁₀CXCX₄CX₅CXCX₂CX₃C, (SEQ ID NO: 60) CX₁₆CX₅CXC, (SEQ ID NO: 61) CX₆CX₄CXCX₄CX₅C, (SEQ ID NO: 62) CX₁₁CX₄CX₅CX₆CX₃C, (SEQ ID NO: 63) CX₈CX₂CX₆CX₅C, (SEQ ID NO: 64) CX₁₀CX₅CX₅CXCX₁₀C, (SEQ ID NO: 65) CX₁₀CXCX₆CX₄CXC, (SEQ ID NO: 66) CX₁₀CX₅CX₅CXCX₂C, (SEQ ID NO: 67) CX₁₄CX₂CX₃CXCXC, (SEQ ID NO: 68) CX₁₅CX₅CXC, (SEQ ID NO: 69) CX₄CX₆CX₈CX₂CX₁₁C, (SEQ ID NO: 70) CX₆CX₄CX₅CX₅CX₁₂C, (SEQ ID NO: 71)CX₇CX₃CXCXCX₄CX₅CX₉C,  (SEQ ID NO: 72) CX₁₀CX₆CX₅C, (SEQ ID NO: 73)CX₇CX₃CX₅CX₅CX₉C,  (SEQ ID NO: 74) CX₇CX₅CXCX₂C,  (SEQ ID NO: 75)CX₁₀CXCX₆C,  (SEQ ID NO: 76) CX₁₀CX₃CX₃CX₅CX₇CXCX₆C,  (SEQ ID NO: 77)CX₁₀CX₄CX₅CX₁₂CX₂C,  (SEQ ID NO: 78) CX₁₂CX₄CX₅CXCXCX₉CX₃C, (SEQ ID NO: 79) CX₁₂CX₄CX₅CX₁₂CX₂C,  (SEQ ID NO: 80) CX₁₀CX₆CX₅CXCX₁₁C, (SEQ ID NO: 81) CX₁₆CX₅CXCXCX₁₄C,  (SEQ ID NO: 82) CX₁₀CX₅CXCX₈CX₆C, (SEQ ID NO: 83) CX₁₂CX₄CX₅CX₈CX₂C, (SEQ ID NO: 84) CX₁₂CX₅CX₅CXCX₈C, (SEQ ID NO: 85) CX₁₀CX₆CX₅CXCX₄CXCX₉C, (SEQ ID NO: 86)CX₁₁CX₄CX₅CX₈CX₂C, (SEQ ID NO: 87) CX₁₀CX₆CX₅CX₈CX₂C, (SEQ ID NO: 88)CX₁₀CX₆CX₅CXCX₈C,  (SEQ ID NO: 89) CX₁₀CX₆CX₅CXCX₃CX₈CX₂C,(SEQ ID NO: 90) CX₁₀CX₆CX₅CX₃CX₈C,  (SEQ ID NO: 91)CX₁₀CX₆CX₅CXCX₂CX₆CX₅C, (SEQ ID NO: 92) CX₇CX₆CX₃CX₃CX₉C, (SEQ ID NO: 93) CX₉CX₈CX₅CX₆CX₅C, (SEQ ID NO: 94)CX₁₀CX₂CX₂CX₇CXCX₁₁CX₅C,  and  (SEQ ID NO: 95) CX₁₀CX₆CX₅CXCX₂CX₈CX₄C.

In some embodiments of each or any of the above or below mentionedembodiments, the cysteine motif is selected from the group consistingof:

(SEQ ID NO: 96) CCX₃CXCX₃CX₂CCXCX₅CX₉CX₅CXC,  (SEQ ID NO: 97)CX₆CX₂CX₅CX₄CCXCX₄CX₆CXC,  (SEQ ID NO: 98) CX₇CXCX₅CX₄CCCX₄CX₆CXC,(SEQ ID NO: 99) CX₉CX₃CXCX₂CXCCCX₆CX₄C,  (SEQ ID NO: 100)CX₅CX₃CXCX₄CX₄CCX₁₀CX₂CC,  (SEQ ID NO: 101) CX₅CXCX₁CXCX₃CCX₃CX₄CX₁₀C,(SEQ ID NO: 102) CX₉CCCX₃CX₄CCCX₅CX₆C,  (SEQ ID NO: 103)CCX₈CX₅CX₄CX₃CX₄CCXCX₁C, (SEQ ID NO: 104) CCX₆CCX₅CCCX₄CX₄CX₁₂C,(SEQ ID NO: 105) CX₆CX₂CX₃CCCX₄CX₅CX₃CX₃C,  (SEQ ID NO: 106)CX₃CX₅CX₆CX₄CCXCX₅CX₄CXC,  (SEQ ID NO: 107) CX₄CX₄CCX₄CX₄CXCX₁₁CX₂CXC,(SEQ ID NO: 108) CX₅CX₂CCX₅CX₄CCX₃CCX₇C,  (SEQ ID NO: 109)CX₅CX₅CX₃CX₂CXCCX₄CX₇CXC, (SEQ ID NO: 110) CX₃CX₇CX₃CX₄CCXCX₂CX₅CX₂C,(SEQ ID NO: 111) CX₉CX₃CXCX₄CCX₅CCCX₆C,  (SEQ ID NO: 112)CX₉CX₃CXCX₂CXCCX₆CX₃CX₃C, (SEQ ID NO: 113) CX₈CCXCX₃CCX₃CXCX₃CX₄C,(SEQ ID NO: 114) CX₉CCX₄CX₂CXCCXCX₄CX₃C,  (SEQ ID NO: 115)CX₁₀CXCX₃CX₂CXCCX₄CX₅CXC, (SEQ ID NO: 116) CX₉CXCX₃CX₂CXCCX₄CX₅CXC,(SEQ ID NO: 117) CX₆CCXCX₅CX₄CCXCX₅CX₂C,  (SEQ ID NO: 118)CX₆CCXCX₃CXCCX₃CX₄CC, (SEQ ID NO: 119) CX₆CCXCX₃CXCX₂CXCX₄CX₈C,(SEQ ID NO: 120) CX₄CX₂CCX₃CXCX₄CCX₂CX₃C,  (SEQ ID NO: 121)CX₃CX₅CX₃CCCX₄CX₉C,  (SEQ ID NO: 122) CCX₉CX₃CXCCX₃CX₅C, (SEQ ID NO: 123) CX₉CX₂CX₃CX₄CCX₄CX₅C,  (SEQ ID NO: 124)CX₉CX₇CX₄CCXCX₇CX₃C,  (SEQ ID NO: 125) CX₉CX₃CCCX₁₀CX₂CX₃C, (SEQ ID NO: 126) CX₃CX₅CX₅CX₄CCX₁₀CX₆C,  (SEQ ID NO: 127)CX₉CX₅CX₄CCXCX₅CX₄C,  (SEQ ID NO: 128) CX₇CXCX₆CX₄CCCX₁₀C, (SEQ ID NO: 129) CX₈CX₂CX₄CCX₄CX₃CX₃C,  (SEQ ID NO: 130)CX₇CX₅CXCX₄CCX₇CX₄C,  (SEQ ID NO: 131) CX₁₁CX₃CX₄CCCX₉CX₂C, (SEQ ID NO: 132) CX₂CX₃CX₄CCX₄CX₅CX₁₅C,  (SEQ ID NO: 133)CX₉CX₅CX₄CCX₇C,  (SEQ ID NO: 134) CX₉CX₇CX₃CX₂CX₆C,  (SEQ ID NO: 135)CX₉CX₅CX₄CCX₁₄C, (SEQ ID NO: 136) CX₉CX₅CX₄CCX₉C, (SEQ ID NO: 137)CX₉CX₆CX₄CCXC, (SEQ ID NO: 138) CX₅CCX₇CX₄CX₁₂,  (SEQ ID NO: 139)CX₁₀CX₃CX₄CCX₄C, (SEQ ID NO: 140) CX₉CX₄CCX₅CX₄C,  (SEQ ID NO: 141)CX₁₀CX₃CX₄CX₇CXC, (SEQ ID NO: 142) CX₇CX₇CX₂CX₂CX₃C,  (SEQ ID NO: 143)CX₉CX₄CX₄CCX₆C, (SEQ ID NO: 144) CX₇CXCX₃CXCX₆C,  (SEQ ID NO: 145)CX₇CXCX₄CXCX₄C, (SEQ ID NO: 146) CX₉CX₅CX₄C,  (SEQ ID NO: 147)CX₃CX₆CX₉C,  (SEQ ID NO: 148) CX₁₀CXCX₄C,  (SEQ ID NO: 149) CX₁₀CCX₄C, (SEQ ID NO: 150) CX₁₅C,  (SEQ ID NO: 151) CX₁₀C,  and  (SEQ ID NO: 152)CX₉C.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises 2 to 6 disulfide bonds.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises SEQ ID NO: 40 or a derivativethereof.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises amino acid residues 3-6 of anyof one SEQ ID NO: 1-4.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises a non-human DH or a derivativethereof.

In some embodiments of each or any of the above or below mentionedembodiments, the non-human DH is SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO:7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, or SEQ IDNO: 12.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises a JH sequence or a derivativethereof.

In some embodiments of each or any of the above or below mentionedembodiments, the JH sequence is SEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO:15, SEQ ID NO: 16, or SEQ ID NO: 17.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises: a non-human or human VHsequence (e.g., a germline VH) or a derivative thereof; a non-human DHsequence or a derivative thereof; and/or JH sequence or derivativethereof.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises an additional amino acidsequence comprising two to six amino acid residues or more positionedbetween the VH sequence and the DH sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the additional amino acid sequence is selected from thegroup consisting of: IR, IF, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20or SEQ ID NO: 21.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises a sequence derived from orbased on SEQ ID NO: 22, SEQ ID NO: 23, SEQ ID NO: 24, SEQ ID NO: 25, SEQID NO: 26, SEQ ID NO: 27, or SEQ ID NO: 28.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises a bovine sequence, anon-bovine sequence, an antibody sequence, or a non-antibody sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the non-antibody sequence is a synthetic sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the non-antibody sequence is a cytokine sequence, alymphokine sequence, a chemokine sequence, a growth factor sequence, ahormone sequence, or a toxin sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the non-antibody sequence is an IL-8 sequence, an IL-21sequence, an SDF-1 (alpha) sequence, a somatostatin sequence, achlorotoxin sequence, a Pro-TxII sequence, or a ziconotide sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the non-antibody sequence is any one of SEQ ID NOS:475-481.

In some embodiments of each or any of the above or below mentionedembodiments, the non-antibody sequence replaces at least a portion ofthe ultralong CDR3.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises a X¹X²X³X⁴X⁵ motif, wherein X¹is threonine (T), glycine (G), alanine (A), serine (S), or valine (V),wherein X² is serine (S), threonine (T), proline (P), isoleucine (I),alanine (A), valine (V), or asparagine (N), wherein X³ is valine (V),alanine (A), threonine (T), or aspartic acid (D), wherein X⁴ ishistidine (H), threonine (T), arginine (R), tyrosine (Y), phenylalanine(F), or leucine (L), and wherein X⁵ is glutamine (Q).

In some embodiments of each or any of the above or below mentionedembodiments, the X¹X²X³X⁴X⁵ motif is TTVHQ (SEQ ID NO: 153), TSVHQ (SEQID NO: 154), SSVTQ (SEQ ID NO: 155), STVHQ (SEQ ID NO: 156), ATVRQ (SEQID NO: 157), TTVYQ (SEQ ID NO: 158), SPVHQ (SEQ ID NO: 159), ATVYQ (SEQID NO: 160), TAVYQ (SEQ ID NO: 161), TNVHQ (SEQ ID NO: 162), ATVHQ (SEQID NO: 163), STVYQ (SEQ ID NO: 164), TIVHQ (SEQ ID NO: 165), AIVYQ (SEQID NO: 166), TTVFQ (SEQ ID NO: 167), AAVFQ (SEQ ID NO: 168), GTVHQ (SEQID NO: 169), ASVHQ (SEQ ID NO: 170), TAVFQ (SEQ ID NO: 171), ATVFQ (SEQID NO: 172), AAAHQ (SEQ ID NO: 173), VVVYQ (SEQ ID NO: 174), GTVFQ (SEQID NO: 175), TAVHQ (SEQ ID NO: 176), ITVHQ (SEQ ID NO: 177), ITAHQ (SEQID NO: 178), VTVHQ (SEQ ID NO: 179); AAVHQ (SEQ ID NO: 180), GTVYQ (SEQID NO: 181), TTVLQ (SEQ ID NO: 182), TTTHQ (SEQ ID NO: 183), or TTDYQ(SEQ ID NO: 184).

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises a CX¹X²X³X⁴X⁵ motif.

In some embodiments of each or any of the above or below mentionedembodiments, the CX¹X²X³X⁴X⁵ motif is CTTVHQ (SEQ ID NO: 185), CTSVHQ(SEQ ID NO: 186), CSSVTQ (SEQ ID NO: 187), CSTVHQ (SEQ ID NO: 188),CATVRQ (SEQ ID NO: 189), CTTVYQ (SEQ ID NO: 190), CSPVHQ (SEQ ID NO:191), CATVYQ (SEQ ID NO: 192), CTAVYQ (SEQ ID NO: 193), CTNVHQ (SEQ IDNO: 194), CATVHQ (SEQ ID NO: 195), CSTVYQ (SEQ ID NO: 196), CTIVHQ (SEQID NO: 197), CAIVYQ (SEQ ID NO: 198), CTTVFQ (SEQ ID NO: 199), CAAVFQ(SEQ ID NO: 200), CGTVHQ (SEQ ID NO: 201), CASVHQ (SEQ ID NO: 202),CTAVFQ (SEQ ID NO: 203), CATVFQ (SEQ ID NO: 204), CAAAHQ (SEQ ID NO:205), CVVVYQ (SEQ ID NO: 206), CGTVFQ (SEQ ID NO: 207), CTAVHQ (SEQ IDNO: 208), CITVHQ (SEQ ID NO: 209), CITAHQ (SEQ ID NO: 210), CVTVHQ (SEQID NO: 211); CAAVHQ (SEQ ID NO: 212), CGTVYQ (SEQ ID NO: 213), CTTVLQ(SEQ ID NO: 214), CTTTHQ (SEQ ID NO: 215), or CTTDYQ (SEQ ID NO: 216).

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises a (X^(a)X^(b))_(z) motif,wherein X^(a) is any amino acid residue, X^(b) is an aromatic amino acidselected from the group consisting of: tyrosine (Y), phenylalanine (F),tryptophan (W), and histidine (H), and wherein z is 1-4.

In some embodiments of each or any of the above or below mentionedembodiments, the (X^(a)X^(b))_(z) motif is CYTYNYEF (SEQ ID NO: 217),HYTYTYDF (SEQ ID NO: 218), HYTYTYEW (SEQ ID NO: 219), KHRYTYEW (SEQ IDNO: 220), NYIYKYSF (SEQ ID NO: 221), PYIYTYQF (SEQ ID NO: 222), SFTYTYEW(SEQ ID NO: 223), SYIYIYQW (SEQ ID NO: 224), SYNYTYSW (SEQ ID NO: 225),SYSYSYEY (SEQ ID NO: 226), SYTYNYDF (SEQ ID NO: 227), SYTYNYEW (SEQ IDNO: 228), SYTYNYQF (SEQ ID NO: 229), SYVWTHNF (SEQ ID NO: 230), TYKYVYEW(SEQ ID NO: 231), TYTYTYEF (SEQ ID NO: 232), TYTYTYEW (SEQ ID NO: 233),VFTYTYEF (SEQ ID NO: 234), AYTYEW (SEQ ID NO: 235), DYIYTY (SEQ ID NO:236), IHSYEF (SEQ ID NO: 237), SFTYEF (SEQ ID NO: 238), SHSYEF (SEQ IDNO: 239), THTYEF (SEQ ID NO: 240), TWTYEF (SEQ ID NO: 241), TYNYEW (SEQID NO: 242), TYSYEF (SEQ ID NO: 243), TYSYEH (SEQ ID NO: 244), TYTYDF(SEQ ID NO: 245), TYTYEF (SEQ ID NO: 246), TYTYEW (SEQ ID NO: 247), AYEF(SEQ ID NO: 248), AYSF (SEQ ID NO: 249), AYSY (SEQ ID NO: 250), CYSF(SEQ ID NO: 251), DYTY (SEQ ID NO: 252), KYEH (SEQ ID NO: 253), KYEW(SEQ ID NO: 254), MYEF (SEQ ID NO: 255), NWIY (SEQ ID NO: 256), NYDY(SEQ ID NO: 257), NYQW (SEQ ID NO: 258), NYSF (SEQ ID NO: 259), PYEW(SEQ ID NO: 260), RYNW (SEQ ID NO: 261), RYTY (SEQ ID NO: 262), SYEF(SEQ ID NO: 263), SYEH (SEQ ID NO: 264), SYEW (SEQ ID NO: 265), SYKW(SEQ ID NO: 266), SYTY (SEQ ID NO: 267), TYDF (SEQ ID NO: 268), TYEF(SEQ ID NO: 269), TYEW (SEQ ID NO: 270), TYQW (SEQ ID NO: 271), TYTY(SEQ ID NO: 272), or VYEW (SEQ ID NO: 273).

In some embodiments of each or any of the above or below mentionedembodiments, the (X^(a)X^(b))_(z) motif is YXYXYX.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises a X¹X²X³X⁴X⁵X_(n) motif,wherein X₁ is threonine (T), glycine (G), alanine (A), serine (S), orvaline (V), wherein X₂ is serine (S), threonine (T), proline (P),isoleucine (I), alanine (A), valine (V), or asparagine (N), wherein X₃is valine (V), alanine (A), threonine (T), or aspartic acid (D), whereinX₄ is histidine (H), threonine (T), arginine (R), tyrosine (Y),phenylalanine (F), or leucine (L), wherein X₅ is glutamine (Q), andwherein n is 27-54.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises X_(n)(X^(a)X^(b))_(z) motif,wherein X^(a) is any amino acid residue, X^(b) is an aromatic amino acidselected from the group consisting of: tyrosine (Y), phenylalanine (F),tryptophan (W), and histidine (H), wherein n is 27-54, and wherein z is1-4.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises aX¹X²X³X⁴X⁵X_(n)(X^(a)X^(b))_(z) motif, wherein X¹ is threonine (T),glycine (G), alanine (A), serine (S), or valine (V), wherein X² isserine (S), threonine (T), proline (P), isoleucine (I), alanine (A),valine (V), or asparagine (N), wherein X³ is valine (V), alanine (A),threonine (T), or aspartic acid (D), wherein X⁴ is histidine (H),threonine (T), arginine (R), tyrosine (Y), phenylalanine (F), or leucine(L), and wherein X⁵ is glutamine (Q), wherein X^(a) is any amino acidresidue, X^(b) is an aromatic amino acid selected from the groupconsisting of: tyrosine (Y), phenylalanine (F), tryptophan (W), andhistidine (H), wherein n is 27-54, and wherein z is 1-4.

In some embodiments of each or any of the above or below mentionedembodiments, the X¹X²X³X⁴X⁵ motif is TTVHQ (SEQ ID NO: 153) or TSVHQ(SEQ ID NO: 154), and wherein the (X^(a)X^(b))_(z) motif is YXYXYX.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises: a CX¹X²X³X⁴X⁵ motif, whereinX¹ is threonine (T), glycine (G), alanine (A), serine (S), or valine(V), wherein X² is serine (S), threonine (T), proline (P), isoleucine(I), alanine (A), valine (V), or asparagine (N), wherein X³ is valine(V), alanine (A), threonine (T), or aspartic acid (D), wherein X⁴ ishistidine (H), threonine (T), arginine (R), tyrosine (Y), phenylalanine(F), or leucine (L), and wherein X⁵ is glutamine (Q); a cysteine motifselected from the group consisting of: CX₁₀CX₅CX₅CXCX₇C (SEQ ID NO: 41),CX₁₀CX₆CX₅CXCX₁₅C (SEQ ID NO: 42), CX₁₁CXCX₅C (SEQ ID NO: 43),CX₁₁CX₅CX₅CXCX₇C (SEQ ID NO: 44), CX₁₀CX₆CX₅CXCX₁₃C (SEQ ID NO: 45),CX₁₀CX₅CXCX₄CX₈C (SEQ ID NO: 46), CX₁₀CX₆CX₆CXCX₇C (SEQ ID NO: 47),CX₁₀CX₄CX₇CXCX₈C (SEQ ID NO: 48), CX₁₀CX₄CX₇CXCX₇C (SEQ ID NO: 49),CX₁₃CX₈CX₈C (SEQ ID NO: 50), CX₁₀CX₆CX₅CXCX₇C (SEQ ID NO: 51),CX₁₀CX₅CX₅C (SEQ ID NO: 52), CX₁₀CX₅CX₆CXCX₇C (SEQ ID NO: 53),CX₁₀CX₆CX₅CX₇CX₉C (SEQ ID NO: 54), CX₉CX₇CX₅CXCX₇C (SEQ ID NO: 55),CX₁₀CX₆CX₅CXCX₉C (SEQ ID NO: 56), CX₁₀CXCX₄CX₅CX₁₁C (SEQ ID NO: 57),CX₇CX₃CX₆CX₅CXCX₅CX₁₀C (SEQ ID NO: 58), CX₁₀CXCX₄CX₅CXCX₂CX₃C (SEQ IDNO: 59), CX₁₆CX₅CXC (SEQ ID NO: 60), CX₆CX₄CXCX₄CX₅C (SEQ ID NO: 61),CX₁₁CX₄CX₅CX₆CX₃C (SEQ ID NO: 62), CX₈CX₂CX₆CX₅C (SEQ ID NO: 63),CX₁₀CX₅CX₅CXCX₁₀C (SEQ ID NO: 64), CX₁₀CXCX₆CX₄CXC (SEQ ID NO: 65),CX₁₀CX₅CX₅CXCX₂C (SEQ ID NO: 66), CX₁₄CX₂CX₃CXCXC (SEQ ID NO: 67),CX₁₅CX₅CXC (SEQ ID NO: 68), CX₄CX₆CX₉CX₂CX₁₁C (SEQ ID NO: 69),CX₆CX₄CX₅CX₅CX₁₂C (SEQ ID NO: 70), CX₇CX₃CXCXCX₄CX₅CX₉C (SEQ ID NO: 71),CX₁₀CX₆CX₅C (SEQ ID NO: 72), CX₇CX₃CX₅CX₅CX₉C (SEQ ID NO: 73),CX₇CX₅CXCX₂C (SEQ ID NO: 74), CX₁₀CXCX₆C (SEQ ID NO: 75),CX₁₀CX₃CX₃CX₅CX₇CXCX₆C (SEQ ID NO: 76), CX₁₀CX₄CX₅CX₁₂CX₂C (SEQ ID NO:77), CX₁₂CX₄CX₅CXCXCX₉CX₃C (SEQ ID NO: 78), CX₁₂CX₄CX₅CX₁₂CX₂C (SEQ IDNO: 79), CX₁₀CX₆CX₅CXCX₁₁C (SEQ ID NO: 80), CX₁₆CX₅CXCXCX₁₄C (SEQ ID NO:81), CX₁₀CX₅CXCX₈CX₆C (SEQ ID NO: 82), CX₁₂CX₄CX₅CX₈CX₂C (SEQ ID NO:83), CX₁₂CX₅CX₅CXCX₈C (SEQ ID NO: 84), CX₁₀CX₆CX₅CXCX₄CXCX₉C (SEQ ID NO:85), CX₁₁CX₄CX₅CX₈CX₂C (SEQ ID NO: 86), CX₁₀CX₆CX₅CX₈CX₂C (SEQ ID NO:87), CX₁₀CX₆CX₅CXCX₈C (SEQ ID NO: 88), CX₁₀CX₆CX₅CXCX₃CX₈CX₂C (SEQ IDNO: 89), CX₁₀CX₆CX₅CX₃CX₈C (SEQ ID NO: 90), CX₁₀CX₆CX₅CXCX₂CX₆CX₅C (SEQID NO: 91), CX₇CX₆CX₃CX₃CX₉C (SEQ ID NO: 92), CX₉CX₈CX₅CX₆CX₅C (SEQ IDNO: 93), CX₁₀CX₂CX₂CX₇CXCX₁₁CX₅C (SEQ ID NO: 94), andCX₁₀CX₆CX₅CXCX₂CX₈CX₄C (SEQ ID NO: 95), and a (X^(a)X^(b))_(z) motif,wherein X^(a) is any amino acid residue, X^(b) is an aromatic amino acidselected from the group consisting of: tyrosine (Y), phenylalanine (F),tryptophan (W), and histidine (H), and wherein z is 1-4.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises: a CX¹X²X³X⁴X⁵ motif, whereinX¹ is threonine (T), glycine (G), alanine (A), serine (S), or valine(V), wherein X² is serine (S), threonine (T), proline (P), isoleucine(I), alanine (A), valine (V), or asparagine (N), wherein X³ is valine(V), alanine (A), threonine (T), or aspartic acid (D), wherein X⁴ ishistidine (H), threonine (T), arginine (R), tyrosine (Y), phenylalanine(F), or leucine (L), and wherein X⁵ is glutamine (Q); a cysteine motifselected from the group consisting of: wherein the cysteine motif isselected from the group consisting of: CCX₃CXCX₃CX₂CCXCX₅CX₉CX₅CXC (SEQID NO: 96), CX₆CX₂CX₅CX₄CCXCX₄CX₆CXC (SEQ ID NO: 97),CX₇CXCX₅CX₄CCCX₄CX₆CXC (SEQ ID NO: 98), CX₉CX₃CXCX₂CXCCCX₆CX₄C (SEQ IDNO: 99), CX₅CX₃CXCX₄CX₄CCX₁₀CX₂CC (SEQ ID NO: 100),CX₅CXCX₁CXCX₃CCX₃CX₄CX₁₀C (SEQ ID NO: 101), CX₉CCCX₃CX₄CCCX₅CX₆C (SEQ IDNO: 102), CCX₈CX₅CX₄CX₃CX₄CCXCX₁C (SEQ ID NO: 103),CCX₆CCX₅CCCX₄CX₄CX₁₂C (SEQ ID NO: 104), CX₆CX₂CX₃CCCX₄CX₅CX₃CX₃C (SEQ IDNO: 105), CX₃CX₅CX₆CX₄CCXCX₅CX₄CXC (SEQ ID NO: 106),CX₄CX₄CCX₄CX₄CXCX₁₁CX₂CXC (SEQ ID NO: 107), CX₅CX₂CCX₅CX₄CCX₃CCX₇C (SEQID NO: 108), CX₅CX₅CX₃CX₂CXCCX₄CX₇CXC (SEQ ID NO: 109),CX₃CX₇CX₃CX₄CCXCX₂CX₅CX₂C (SEQ ID NO: 110), CX₉CX₃CXCX₄CCX₅CCCX₆C (SEQID NO: 111), CX₉CX₃CXCX₂CXCCX₆CX₃CX₃C (SEQ ID NO: 112),CX₈CCXCX₃CCX₃CXCX₃CX₄C (SEQ ID NO: 113), CX₉CCX₄CX₂CXCCXCX₄CX₃C (SEQ IDNO: 114), CX₁₀CXCX₃CX₂CXCCX₄CX₅CXC (SEQ ID NO: 115),CX₉CXCX₃CX₂CXCCX₄CX₅CXC (SEQ ID NO: 116), CX₆CCXCX₅CX₄CCXCX₅CX₂C (SEQ IDNO: 117), CX₆CCXCX₃CXCCX₃CX₄CC (SEQ ID NO: 118), CX₆CCXCX₃CXCX₂CXCX₄CX₈C(SEQ ID NO: 119), CX₄CX₂CCX₃CXCX₄CCX₂CX₃C (SEQ ID NO: 120),CX₃CX₅CX₃CCCX₄CX₉C (SEQ ID NO: 121), CCX₉CX₃CXCCX₃CX₅C (SEQ ID NO: 122),CX₉CX₂CX₃CX₄CCX₄CX₅C (SEQ ID NO: 123), CX₉CX₇CX₄CCXCX₇CX₃C (SEQ ID NO:124), CX₉CX₃CCCX₁₀CX₂CX₃C (SEQ ID NO: 125), CX₃CX₅CX₅CX₄CCX₁₀CX₆C (SEQID NO: 126), CX₉CX₅CX₄CCXCX₅CX₄C (SEQ ID NO: 127), CX₇CXCX₆CX₄CCCX₁₀C(SEQ ID NO: 128), CX₈CX₂CX₄CCX₄CX₃CX₃C (SEQ ID NO: 129),CX₇CX₅CXCX₄CCX₇CX₄C (SEQ ID NO: 130), CX₁₁CX₃CX₄CCCX₈CX₂C (SEQ ID NO:131), CX₂CX₃CX₄CCX₄CX₅CX₁₅C (SEQ ID NO: 132), CX₉CX₅CX₄CCX₇C (SEQ ID NO:133), CX₉CX₇CX₃CX₂CX₆C (SEQ ID NO: 134), CX₉CX₅CX₄CCX₁₄C (SEQ ID NO:135), CX₉CX₅CX₄CCX₈C (SEQ ID NO: 136), CX₉CX₆CX₄CCXC (SEQ ID NO: 137),CX₅CCX₇CX₄CX₁₂ (SEQ ID NO: 138), CX₁₀CX₃CX₄CCX₄C (SEQ ID NO: 139),CX₉CX₄CCX₅CX₄C (SEQ ID NO: 140), CX₁₀CX₃CX₄CX₇CXC (SEQ ID NO: 141),CX₇CX₇CX₂CX₂CX₃C (SEQ ID NO: 142), CX₉CX₄CX₄CCX₆C (SEQ ID NO: 143),CX₇CXCX₃CXCX₆C (SEQ ID NO: 144), CX₇CXCX₄CXCX₄C (SEQ ID NO: 145),CX₉CX₅CX₄C (SEQ ID NO: 146), CX₃CX₆CX₈C (SEQ ID NO: 147), CX₁₀CXCX₄C(SEQ ID NO: 148), CX₁₀CCX₄C (SEQ ID NO: 149), CX₁₅C (SEQ ID NO: 150),CX₁₀C (SEQ ID NO: 151), and CX₉C (SEQ ID NO: 152); and a(X^(a)X^(b))_(z) motif, wherein X^(a) is any amino acid residue, X^(b)is an aromatic amino acid selected from the group consisting of:tyrosine (Y), phenylalanine (F), tryptophan (W), and histidine (H), andwherein z is 1-4.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises an additional sequence that isa linker.

In some embodiments of each or any of the above or below mentionedembodiments, the linker is linked to a C-terminus, a N-terminus, or bothC-terminus and N-terminus of the non-antibody sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 is a ruminant CDR3.

In some embodiments of each or any of the above or below mentionedembodiments, the ruminant is a cow.

In some embodiments of each or any of the above or below mentionedembodiments, the humanized antibody or binding fragment thereofcomprises a human heavy chain variable region framework sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the humanized antibody or binding fragment thereofcomprises a human heavy chain germline sequence or is a derived from ahuman heavy chain germline sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the humanized antibody or binding fragment thereofcomprises a human heavy chain germline sequence that is a VH4 familymember germline sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the humanized antibody or binding fragment thereofcomprises a VH4-34 germline sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the humanized antibody or binding fragment thereofcomprises a human heavy chain germline sequence that is derived from theVH4-34 germline sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the VH4-34 germline sequence comprises a CDR1 comprising aGly31Asp and Tyr32Lys substitution based on Kabat numbering.

In some embodiments of each or any of the above or below mentionedembodiments, the VH4-34 germline sequence comprises a CDR2 comprising aGlu50Ser substitution based on Kabat numbering.

In some embodiments of each or any of the above or below mentionedembodiments, the VH4-34 germline sequence comprises a CDR1 comprisingAla23Thr, Val24Ala, Tyr25Ser, Gly27Phe, Phe29Leu, Gly31Asp, Tyr32Lys,Tyr33Ala, Trp34Val, and Ser35Gly substitutions, and a CDR2 comprisingIle48Leu, Glu50Ser, Asn52Asp, His53Thr, Ser54Gly, Ser56Asn, and Asn58Glysubstitutions, based on Kabat numbering.

In some embodiments of each or any of the above or below mentionedembodiments, the humanized antibody or binding fragment thereofcomprises the amino acid sequence set forth in SEQ ID NO: 461, 462, 463,464, 465, 466, 467, 468, or 469.

In some embodiments of each or any of the above or below mentionedembodiments, the humanized antibody or binding fragment thereofcomprises the amino acid sequence set forth in SEQ ID NO: 470.

In some embodiments of each or any of the above or below mentionedembodiments, the humanized antibody or binding fragment thereofcomprises the amino acid sequence set forth in SEQ ID NO: 461, 462, 463,464, 465, 466, 467, 468, or 469; and the amino acid sequence set forthin SEQ ID NO: 470.

In some embodiments of each or any of the above or below mentionedembodiments, the humanized antibody or binding fragment thereofcomprises the amino acid sequence set forth in SEQ ID NO: 461, 462, 463,464, 465, 466, 467, 468, or 469; the amino acid sequence set forth inSEQ ID NO: 470; and a peptide sequence, wherein the peptide sequence ispositioned between SEQ ID NO: 461, 462, 463, 464, 465, 466, 467, 468, or469, and SEQ ID NO: 470.

In some embodiments of each or any of the above or below mentionedembodiments, the peptide sequence is a bovine sequence, a non-bovinesequence, an antibody sequence, or a non-antibody sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the humanized antibody or binding fragment thereofcomprises a human light chain variable region framework sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the humanized antibody or binding fragment thereofcomprises a light chain variable region sequence that is a lambda lightchain variable region sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the lambda light chain variable region sequence is a bovinelambda light chain variable region sequence or derived from a bovinelambda light chain variable region sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the lambda light chain variable region sequence is a humanlambda light chain variable region sequence or derived from a humanlambda light chain variable region sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the human lambda light chain variable region sequence is aVL1-51 germline sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the human lambda light chain variable region sequence isderived from a VL1-51 germline sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the VL1-51 germline sequence comprises a CDR1 comprisingIle29Val and Asn32Gly substitution based on Kabat numbering.

In some embodiments of each or any of the above or below mentionedembodiments, the VL1-51 germline sequence comprises a CDR2 comprising asubstitution of DNN to GDT.

In some embodiments of each or any of the above or below mentionedembodiments, the VL1-51 germline sequence comprises a CDR2 comprising asubstitution of DNNKRP (SEQ ID NO: 471) to GDTSRA (SEQ ID NO: 472).

In some embodiments of each or any of the above or below mentionedembodiments, the VL1-51 germline sequence comprises a S2A, T5N, P8S,A12G, A13S, and P14L substitution based on Kabat numbering.

In some embodiments of each or any of the above or below mentionedembodiments, the VL1-51 germline sequence comprises a S2A, T5N, P8S,A12G, A13S, and P14L substitution based on Kabat numbering, and a CDR2comprising a substitution of DNN to GDT.

In some embodiments of each or any of the above or below mentionedembodiments, the humanized antibody or binding fragment thereofcomprising the amino acid sequence set forth in SEQ ID NO: 440, 441,442, 443, or 444.

The present disclosure also provides polynucleotides encoding thehumanized antibody or binding fragment thereof disclosed herein.

The present disclosure also provides polynucleotides encoding ahumanized antibody or binding fragment thereof that comprises anultralong CDR3.

The present disclosure also provides polynucleotides encoding ahumanized variable region that comprises an ultralong CDR3.

The present disclosure also provides vectors that comprise thepolynucleotides disclosed herein.

The present disclosure also provides host cells comprising the vectorsdisclosed herein.

The present disclosure also provides a nucleic acid library comprising aplurality of polynucleotides comprising sequences coding for humanizedantibodies or binding fragments thereof, wherein the antibodies orbinding fragments thereof comprise an ultralong CDR3.

The present disclosure also provides a library of humanized antibodiesor binding fragments thereof, wherein the antibodies or bindingfragments thereof comprise an ultralong CDR3.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 is 35 amino acids in length or longer,40 amino acids in length or longer, 45 amino acids in length or longer,50 amino acids in length or longer, 55 amino acids in length or longer,or 60 amino acids in length or longer.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 is 35 amino acids in length or longer.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises 3 or more cysteine residues, 4or more cysteine residues, 5 or more cysteine residues, 6 or morecysteine residues, 7 or more cysteine residues, 8 or more cysteineresidues, 9 or more cysteine residues, 10 or more cysteine residues, 11or more cysteine residues, or 12 or more cysteine residues.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises 3 or more cysteine residues.

In some embodiments of each or any of the above or below mentionedembodiments, the antibodies or binding fragments thereof comprise acysteine motif.

In some embodiments of each or any of the above or below mentionedembodiments, the cysteine motif is selected from the group consistingof:

(SEQ ID NO: 41) CX₁₀CX₅CX₅CXCX₇C, (SEQ ID NO: 42) CX₁₀CX₆CX₅CXCX₁₅C,(SEQ ID NO: 43) CX₁₁CXCX₅C,  (SEQ ID NO: 44) CX₁₁CX₅CX₅CXCX₇C,(SEQ ID NO: 45) CX₁₀CX₆CX₅CXCX₁₃C, (SEQ ID NO: 46) CX₁₀CX₅CXCX₄CX₈C,(SEQ ID NO: 47) CX₁₀CX₆CX₆CXCX₇C, (SEQ ID NO: 48) CX₁₀CX₄CX₇CXCX₈C,(SEQ ID NO: 49) CX₁₀CX₄CX₇CXCX₇C,  (SEQ ID NO: 50) CX₁₃CX₈CX₈C,(SEQ ID NO: 51) CX₁₀CX₆CX₅CXCX₇C,  (SEQ ID NO: 52) CX₁₀CX₅CX₅C,(SEQ ID NO: 53) CX₁₀CX₅CX₆CXCX₇C,  (SEQ ID NO: 54) CX₁₀CX₆CX₅CX₇CX₉C,(SEQ ID NO: 55) CX₉CX₇CX₅CXCX₇C,  (SEQ ID NO: 56) CX₁₀CX₆CX₅CXCX₉C,(SEQ ID NO: 57) CX₁₀CXCX₄CX₅CX₁₁C,  (SEQ ID NO: 58)CX₇CX₃CX₆CX₅CXCX₅CX₁₀C, (SEQ ID NO: 59) CX₁₀CXCX₄CX₅CXCX₂CX₃C, (SEQ ID NO: 60) CX₁₆CX₅CXC, (SEQ ID NO: 61) CX₆CX₄CXCX₄CX₅C, (SEQ ID NO: 62) CX₁₁CX₄CX₅CX₆CX₃C, (SEQ ID NO: 63) CX₈CX₂CX₆CX₅C, (SEQ ID NO: 64) CX₁₀CX₅CX₅CXCX₁₀C, (SEQ ID NO: 65) CX₁₀CXCX₆CX₄CXC, (SEQ ID NO: 66) CX₁₀CX₅CX₅CXCX₂C, (SEQ ID NO: 67) CX₁₄CX₂CX₃CXCXC, (SEQ ID NO: 68) CX₁₅CX₅CXC, (SEQ ID NO: 69) CX₄CX₆CX₉CX₂CX₁₁C, (SEQ ID NO: 70) CX₆CX₄CX₅CX₅CX₁₂C, (SEQ ID NO: 71)CX₇CX₃CXCXCX₄CX₅CX₉C,  (SEQ ID NO: 72) CX₁₀CX₆CX₅C, (SEQ ID NO: 73)CX₇CX₃CX₅CX₅CX₉C,  (SEQ ID NO: 74) CX₇CX₅CXCX₂C,  (SEQ ID NO: 75)CX₁₀CXCX₆C,  (SEQ ID NO: 76) CX₁₀CX₃CX₃CX₅CX₇CXCX₆C,  (SEQ ID NO: 77)CX₁₀CX₄CX₅CX₁₂CX₂C,  (SEQ ID NO: 78) CX₁₂CX₄CX₅CXCXCX₉CX₃C, (SEQ ID NO: 79) CX₁₂CX₄CX₅CX₁₂CX₂C,  (SEQ ID NO: 80) CX₁₀CX₆CX₅CXCX₁₁C, (SEQ ID NO: 81) CX₁₆CX₅CXCXCX₁₄C,  (SEQ ID NO: 82) CX₁₀CX₅CXCX₈CX₆C, (SEQ ID NO: 83) CX₁₂CX₄CX₅CX₈CX₂C, (SEQ ID NO: 84) CX₁₂CX₅CX₅CXCX₈C, (SEQ ID NO: 85) CX₁₀CX₆CX₅CXCX₄CXCX₉C, (SEQ ID NO: 86)CX₁₁CX₄CX₅CX₈CX₂C,  (SEQ ID NO: 87) CX₁₀CX₆CX₅CX₈CX₂C, (SEQ ID NO: 88)CX₁₀CX₆CX₅CXCX₈C,  (SEQ ID NO: 89) CX₁₀CX₆CX₅CXCX₃CX₈CX₂C,(SEQ ID NO: 90) CX₁₀CX₆CX₅CX₃CX₈C,  (SEQ ID NO: 91)CX₁₀CX₆CX₅CXCX₂CX₆CX₅C, (SEQ ID NO: 92) CX₇CX₆CX₃CX₃CX₉C, (SEQ ID NO: 93) CX₉CX₈CX₅CX₆CX₅C, (SEQ ID NO: 94)CX₁₀CX₂CX₂CX₇CXCX₁₁CX₅C,  and  (SEQ ID NO: 95) CX₁₀CX₆CX₅CXCX₂CX₈CX₄C.

In some embodiments of each or any of the above or below mentionedembodiments, the cysteine motif is selected from the group consistingof:

(SEQ ID NO: 96) CCX₃CXCX₃CX₂CCXCX₅CX₉CX₅CXC,  (SEQ ID NO: 97)CX₆CX₂CX₅CX₄CCXCX₄CX₆CXC, (SEQ ID NO: 98) CX₇CXCX₅CX₄CCCX₄CX₆CXC,(SEQ ID NO: 99) CX₉CX₃CXCX₂CXCCCX₆CX₄C,  (SEQ ID NO: 100)CX₅CX₃CXCX₄CX₄CCX₁₀CX₂CC, (SEQ ID NO: 101) CX₅CXCX₁CXCX₃CCX₃CX₄CX₁₀C,(SEQ ID NO: 102) CX₉CCCX₃CX₄CCCX₅CX₆C,  (SEQ ID NO: 103)CCX₉CX₅CX₄CX₃CX₄CCXCX₁C, (SEQ ID NO: 104) CCX₆CCX₅CCCX₄CX₄CX₁₂C,(SEQ ID NO: 105) CX₆CX₂CX₃CCCX₄CX₅CX₃CX₃C,  (SEQ ID NO: 106)CX₃CX₅CX₆CX₄CCXCX₅CX₄CXC,  (SEQ ID NO: 107) CX₄CX₄CCX₄CX₄CXCX₁₁CX₂CXC,(SEQ ID NO: 108) CX₅CX₂CCX₅CX₄CCX₃CCX₇C,  (SEQ ID NO: 109)CX₅CX₅CX₃CX₂CXCCX₄CX₇CXC,  (SEQ ID NO: 110) CX₃CX₇CX₃CX₄CCXCX₂CX₅CX₂C,(SEQ ID NO: 111) CX₉CX₃CXCX₄CCX₅CCCX₆C,  (SEQ ID NO: 112)CX₉CX₃CXCX₂CXCCX₆CX₃CX₃C, (SEQ ID NO: 113) CX₈CCXCX₃CCX₃CXCX₃CX₄C,(SEQ ID NO: 114) CX₉CCX₄CX₂CXCCXCX₄CX₃C,  (SEQ ID NO: 115)CX₁₀CXCX₃CX₂CXCCX₄CX₅CXC, (SEQ ID NO: 116) CX₉CXCX₃CX₂CXCCX₄CX₅CXC,(SEQ ID NO: 117) CX₆CCXCX₅CX₄CCXCX₅CX₂C,  (SEQ ID NO: 118)CX₆CCXCX₃CXCCX₃CX₄CC, (SEQ ID NO: 119) CX₆CCXCX₃CXCX₂CXCX₄CX₈C,(SEQ ID NO: 120) CX₄CX₂CCX₃CXCX₄CCX₂CX₃C,  (SEQ ID NO: 121)CX₃CX₅CX₃CCCX₄CX₉C,  (SEQ ID NO: 122) CCX₉CX₃CXCCX₃CX₅C, (SEQ ID NO: 123) CX₉CX₂CX₃CX₄CCX₄CX₅C,  (SEQ ID NO: 124)CX₉CX₇CX₄CCXCX₇CX₃C,  (SEQ ID NO: 125) CX₉CX₃CCCX₁₀CX₂CX₃C, (SEQ ID NO: 126) CX₃CX₅CX₅CX₄CCX₁₀CX₆C,  (SEQ ID NO: 127)CX₉CX₅CX₄CCXCX₅CX₄C,  (SEQ ID NO: 128) CX₇CXCX₆CX₄CCCX₁₀C, (SEQ ID NO: 129) CX₈CX₂CX₄CCX₄CX₃CX₃C,  (SEQ ID NO: 130)CX₇CX₅CXCX₄CCX₇CX₄C,  (SEQ ID NO: 131) CX₁₁CX₃CX₄CCCX₈CX₂C, (SEQ ID NO: 132) CX₂CX₃CX₄CCX₄CX₅CX₁₅C,  (SEQ ID NO: 133)CX₉CX₅CX₄CCX₇C,  (SEQ ID NO: 134) CX₉CX₇CX₃CX₂CX₆C,  (SEQ ID NO: 135)CX₉CX₅CX₄CCX₁₄C, (SEQ ID NO: 136) CX₉CX₅CX₄CCX₈C, (SEQ ID NO: 137)CX₉CX₆CX₄CCXC, (SEQ ID NO: 138) CX₅CCX₇CX₄CX₁₂,  (SEQ ID NO: 139)CX₁₀CX₃CX₄CCX₄C, (SEQ ID NO: 140) CX₉CX₄CCX₅CX₄C,  (SEQ ID NO: 141)CX₁₀CX₃CX₄CX₇CXC, (SEQ ID NO: 142) CX₇CX₇CX₂CX₂CX₃C,  (SEQ ID NO: 143)CX₉CX₄CX₄CCX₆C, (SEQ ID NO: 144) CX₇CXCX₃CXCX₆C,  (SEQ ID NO: 145)CX₇CXCX₄CXCX₄C, (SEQ ID NO: 146) CX₉CX₅CX₄C,  (SEQ ID NO: 147)CX₃CX₆CX₈C,  (SEQ ID NO: 148) CX₁₀CXCX₄C,  (SEQ ID NO: 149) CX₁₀CCX₄C, (SEQ ID NO: 150) CX₁₅C,  (SEQ ID NO: 151) CX₁₀C,  and  (SEQ ID NO: 152)CX₉C.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises 2 to 6 disulfide bonds.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises SEQ ID NO: 40 or a derivativethereof.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises amino acid residues 3-6 of anyof one SEQ ID NO: 1-4.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises a non-human DH or a derivativethereof.

In some embodiments of each or any of the above or below mentionedembodiments, the non-human DH is SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO:7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, or SEQ IDNO: 12.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises a JH sequence or a derivativethereof.

In some embodiments of each or any of the above or below mentionedembodiments, the JH sequence is SEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO:15, SEQ ID NO: 16, or SEQ ID NO: 17.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises: a non-human VH sequence or aderivative thereof; a non-human DH sequence or a derivative thereof;and/or a JH sequence or derivative thereof.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises an additional amino acidsequence comprising two to six amino acid residues or more positionedbetween the VH sequence and the DH sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the additional amino acid sequence is selected from thegroup consisting of: IR, IF, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20or SEQ ID NO: 21.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises a sequence derived from orbased on SEQ ID NO: 22, SEQ ID NO: 23, SEQ ID NO: 24, SEQ ID NO: 25, SEQID NO: 26, SEQ ID NO: 27, or SEQ ID NO: 28.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises a non-bovine sequence or anon-antibody sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the non-antibody sequence is a synthetic sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the non-antibody sequence is a cytokine sequence, alymphokine sequence, a chemokine sequence, a growth factor sequence, ahormone sequence, or a toxin sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the non-antibody sequence is an IL-8 sequence, an IL-21sequence, an SDF-1 (alpha) sequence, a somatostatin sequence, achlorotoxin sequence, a Pro-TxII sequence, or a ziconotide sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the non-antibody sequence is any one of SEQ ID NOS:475-481.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises a X¹X²X³X⁴X⁵ motif, wherein X¹is threonine (T), glycine (G), alanine (A), serine (S), or valine (V),wherein X² is serine (S), threonine (T), proline (P), isoleucine (I),alanine (A), valine (V), or asparagine (N), wherein X³ is valine (V),alanine (A), threonine (T), or aspartic acid (D), wherein X⁴ ishistidine (H), threonine (T), arginine (R), tyrosine (Y), phenylalanine(F), or leucine (L), and wherein X⁵ is glutamine (Q).

In some embodiments of each or any of the above or below mentionedembodiments, the X¹X²X³X⁴X⁵ motif is TTVHQ (SEQ ID NO: 153), TSVHQ (SEQID NO: 154), SSVTQ (SEQ ID NO: 155), STVHQ (SEQ ID NO: 156), ATVRQ (SEQID NO: 157), TTVYQ (SEQ ID NO: 158), SPVHQ (SEQ ID NO: 159), ATVYQ (SEQID NO: 160), TAVYQ (SEQ ID NO: 161), TNVHQ (SEQ ID NO: 162), ATVHQ (SEQID NO: 163), STVYQ (SEQ ID NO: 164), TIVHQ (SEQ ID NO: 165), AIVYQ (SEQID NO: 166), TTVFQ (SEQ ID NO: 167), AAVFQ (SEQ ID NO: 168), GTVHQ (SEQID NO: 169), ASVHQ (SEQ ID NO: 170), TAVFQ (SEQ ID NO: 171), ATVFQ (SEQID NO: 172), AAAHQ (SEQ ID NO: 173), VVVYQ (SEQ ID NO: 174), GTVFQ (SEQID NO: 175), TAVHQ (SEQ ID NO: 176), ITVHQ (SEQ ID NO: 177), ITAHQ (SEQID NO: 178), VTVHQ (SEQ ID NO: 179); AAVHQ (SEQ ID NO: 180), GTVYQ (SEQID NO: 181), TTVLQ (SEQ ID NO: 182), TTTHQ (SEQ ID NO: 183), or TTDYQ(SEQ ID NO: 184).

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises a CX¹X²X³X⁴X⁵ motif.

In some embodiments of each or any of the above or below mentionedembodiments, the CX¹X²X³X⁴X⁵ motif is CTTVHQ (SEQ ID NO: 185), CTSVHQ(SEQ ID NO: 186), CSSVTQ (SEQ ID NO: 187), CSTVHQ (SEQ ID NO: 188),CATVRQ (SEQ ID NO: 189), CTTVYQ (SEQ ID NO: 190), CSPVHQ (SEQ ID NO:191), CATVYQ (SEQ ID NO: 192), CTAVYQ (SEQ ID NO: 193), CTNVHQ (SEQ IDNO: 194), CATVHQ (SEQ ID NO: 195), CSTVYQ (SEQ ID NO: 196), CTIVHQ (SEQID NO: 197), CAIVYQ (SEQ ID NO: 198), CTTVFQ (SEQ ID NO: 199), CAAVFQ(SEQ ID NO: 200), CGTVHQ (SEQ ID NO: 201), CASVHQ (SEQ ID NO: 202),CTAVFQ (SEQ ID NO: 203), CATVFQ (SEQ ID NO: 204), CAAAHQ (SEQ ID NO:205), CVVVYQ (SEQ ID NO: 206), CGTVFQ (SEQ ID NO: 207), CTAVHQ (SEQ IDNO: 208), CITVHQ (SEQ ID NO: 209), CITAHQ (SEQ ID NO: 210), CVTVHQ (SEQID NO: 211); CAAVHQ (SEQ ID NO: 212), CGTVYQ (SEQ ID NO: 213), CTTVLQ(SEQ ID NO: 214), CTTTHQ (SEQ ID NO: 215), or CTTDYQ (SEQ ID NO: 216).

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises a (X^(a)X^(b))_(z) motif,wherein X^(a) is any amino acid residue, X^(b) is an aromatic amino acidselected from the group consisting of: tyrosine (Y), phenylalanine (F),tryptophan (W), and histidine (H), and wherein z is 1-4.

In some embodiments of each or any of the above or below mentionedembodiments, the (X^(a)X^(b))_(z) motif is CYTYNYEF (SEQ ID NO: 217),HYTYTYDF (SEQ ID NO: 218), HYTYTYEW (SEQ ID NO: 219), KHRYTYEW (SEQ IDNO: 220), NYIYKYSF (SEQ ID NO: 221), PYIYTYQF (SEQ ID NO: 222), SFTYTYEW(SEQ ID NO: 223), SYIYIYQW (SEQ ID NO: 224), SYNYTYSW (SEQ ID NO: 225),SYSYSYEY (SEQ ID NO: 226), SYTYNYDF (SEQ ID NO: 227), SYTYNYEW (SEQ IDNO: 228), SYTYNYQF (SEQ ID NO: 229), SYVWTHNF (SEQ ID NO: 230), TYKYVYEW(SEQ ID NO: 231), TYTYTYEF (SEQ ID NO: 232), TYTYTYEW (SEQ ID NO: 233),VFTYTYEF (SEQ ID NO: 234), AYTYEW (SEQ ID NO: 235), DYIYTY (SEQ ID NO:236), IHSYEF (SEQ ID NO: 237), SFTYEF (SEQ ID NO: 238), SHSYEF (SEQ IDNO: 239), THTYEF (SEQ ID NO: 240), TWTYEF (SEQ ID NO: 241), TYNYEW (SEQID NO: 242), TYSYEF (SEQ ID NO: 243), TYSYEH (SEQ ID NO: 244), TYTYDF(SEQ ID NO: 245), TYTYEF (SEQ ID NO: 246), TYTYEW (SEQ ID NO: 247), AYEF(SEQ ID NO: 248), AYSF (SEQ ID NO: 249), AYSY (SEQ ID NO: 250), CYSF(SEQ ID NO: 251), DYTY (SEQ ID NO: 252), KYEH (SEQ ID NO: 253), KYEW(SEQ ID NO: 254), MYEF (SEQ ID NO: 255), NWIY (SEQ ID NO: 256), NYDY(SEQ ID NO: 257), NYQW (SEQ ID NO: 258), NYSF (SEQ ID NO: 259), PYEW(SEQ ID NO: 260), RYNW (SEQ ID NO: 261), RYTY (SEQ ID NO: 262), SYEF(SEQ ID NO: 263), SYEH (SEQ ID NO: 264), SYEW (SEQ ID NO: 265), SYKW(SEQ ID NO: 266), SYTY (SEQ ID NO: 267), TYDF (SEQ ID NO: 268), TYEF(SEQ ID NO: 269), TYEW (SEQ ID NO: 270), TYQW (SEQ ID NO: 271), TYTY(SEQ ID NO: 272), or VYEW (SEQ ID NO: 273).

In some embodiments of each or any of the above or below mentionedembodiments, the (X^(a)X^(b))_(z) motif is YXYXYX.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises a X¹X²X³X⁴X⁵X_(n) motif,wherein X¹ is threonine (T), glycine (G), alanine (A), serine (S), orvaline (V), wherein X² is serine (S), threonine (T), proline (P),isoleucine (I), alanine (A), valine (V), or asparagine (N), wherein X³is valine (V), alanine (A), threonine (T), or aspartic acid (D), whereinX⁴ is histidine (H), threonine (T), arginine (R), tyrosine (Y),phenylalanine (F), or leucine (L), and wherein X⁵ is glutamine (Q), andwherein n is 27-54.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises X_(n)(X^(a)X^(b))_(z) motif,wherein X^(a) is any amino acid residue, X^(b) is an aromatic amino acidselected from the group consisting of: tyrosine (Y), phenylalanine (F),tryptophan (W), and histidine (H), wherein n is 27-54, and wherein z is1-4.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises aX¹X²X³X⁴X⁵X_(n)(X^(a)X^(b))_(z) motif, wherein X₁ is threonine (T),glycine (G), alanine (A), serine (S), or valine (V), wherein X₂ isserine (S), threonine (T), proline (P), isoleucine (I), alanine (A),valine (V), or asparagine (N), wherein X₃ is valine (V), alanine (A),threonine (T), or aspartic acid (D), wherein X₄ is histidine (H),threonine (T), arginine (R), tyrosine (Y), phenylalanine (F), or leucine(L), wherein X₅ is glutamine (Q), X^(a) is any amino acid residue, X^(b)is an aromatic amino acid selected from the group consisting of:tyrosine (Y), phenylalanine (F), tryptophan (W), and histidine (H),wherein n is 27-54, and wherein z is 1-4.

In some embodiments of each or any of the above or below mentionedembodiments, the X¹X²X³X⁴X⁵ motif is TTVHQ (SEQ ID NO: 153) or TSVHQ(SEQ ID NO: 154), and wherein the (X^(a)X^(b))_(z) motif is YXYXYX.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises: a CX¹X²X³X⁴X⁵ motif, whereinX¹ is threonine (T), glycine (G), alanine (A), serine (S), or valine(V), wherein X² is serine (S), threonine (T), proline (P), isoleucine(I), alanine (A), valine (V), or asparagine (N), wherein X³ is valine(V), alanine (A), threonine (T), or aspartic acid (D), wherein X⁴ ishistidine (H), threonine (T), arginine (R), tyrosine (Y), phenylalanine(F), or leucine (L), and wherein X⁵ is glutamine (Q), a cysteine motifselected from the group consisting of: CX₁₀CX₅CX₅CXCX₇C (SEQ ID NO: 41),CX₁₀CX₆CX₅CXCX₁₅C (SEQ ID NO: 42), CX₁₁CXCX₅C (SEQ ID NO: 43),CX₁₁CX₅CX₅CXCX₇C (SEQ ID NO: 44), CX₁₀CX₆CX₅CXCX₁₃C (SEQ ID NO: 45),CX₁₀CX₅CXCX₄CX₈C (SEQ ID NO: 46), CX₁₀CX₆CX₆CXCX₇C (SEQ ID NO: 47),CX₁₀CX₄CX₇CXCX₈C (SEQ ID NO: 48), CX₁₀CX₄CX₇CXCX₇C (SEQ ID NO: 49),CX₁₃CX₈CX₈C (SEQ ID NO: 50), CX₁₀CX₆CX₅CXCX₇C (SEQ ID NO: 51),CX₁₀CX₅CX₅C (SEQ ID NO: 52), CX₁₀CX₅CX₆CXCX₇C (SEQ ID NO: 53),CX₁₀CX₆CX₅CX₇CX₉C (SEQ ID NO: 54), CX₉CX₇CX₅CXCX₇C (SEQ ID NO: 55),CX₁₀CX₆CX₅CXCX₉C (SEQ ID NO: 56), CX₁₀CXCX₄CX₅CX₁₁C (SEQ ID NO: 57),CX₇CX₃CX₆CX₅CXCX₅CX₁₀C (SEQ ID NO: 58), CX₁₀CXCX₄CX₅CXCX₂CX₃C (SEQ IDNO: 59), CX₁₆CX₅CXC (SEQ ID NO: 60), CX₆CX₄CXCX₄CX₅C (SEQ ID NO: 61),CX₁₁CX₄CX₅CX₆CX₃C (SEQ ID NO: 62), CX₈CX₂CX₆CX₅C (SEQ ID NO: 63),CX₁₀CX₅CX₅CXCX₁₀C (SEQ ID NO: 64), CX₁₀CXCX₆CX₄CXC (SEQ ID NO: 65),CX₁₀CX₅CX₅CXCX₂C (SEQ ID NO: 66), CX₁₄CX₂CX₃CXCXC (SEQ ID NO: 67),CX₁₅CX₅CXC (SEQ ID NO: 68), CX₄CX₆CX₉CX₂CX₁₁C (SEQ ID NO: 69),CX₆CX₄CX₅CX₅CX₁₂C (SEQ ID NO: 70), CX₇CX₃CXCXCX₄CX₅CX₉C (SEQ ID NO: 71),CX₁₀CX₆CX₅C (SEQ ID NO: 72), CX₇CX₃CX₅CX₅CX₉C (SEQ ID NO: 73),CX₇CX₅CXCX₂C (SEQ ID NO: 74), CX₁₀CXCX₆C (SEQ ID NO: 75),CX₁₀CX₃CX₃CX₅CX₇CXCX₆C (SEQ ID NO: 76), CX₁₀CX₄CX₅CX₁₂CX₂C (SEQ ID NO:77), CX₁₂CX₄CX₅CXCXCX₉CX₃C (SEQ ID NO: 78), CX₁₂CX₄CX₅CX₁₂CX₂C (SEQ IDNO: 79), CX₁₀CX₆CX₅CXCX₁₁C (SEQ ID NO: 80), CX₁₆CX₅CXCXCX₁₄C (SEQ ID NO:81), CX₁₀CX₅CXCX₈CX₆C (SEQ ID NO: 82), CX₁₂CX₄CX₅CX₈CX₂C (SEQ ID NO:83), CX₁₂CX₅CX₅CXCX₈C (SEQ ID NO: 84), CX₁₀CX₆CX₅CXCX₄CXCX₉C (SEQ ID NO:85), CX₁₁CX₄CX₅CX₈CX₂C (SEQ ID NO: 86), CX₁₀CX₆CX₅CX₈CX₂C (SEQ ID NO:87), CX₁₀CX₆CX₅CXCX₈C (SEQ ID NO: 88), CX₁₀CX₆CX₅CXCX₃CX₈CX₂C (SEQ IDNO: 89), CX₁₀CX₆CX₅CX₃CX₈C (SEQ ID NO: 90), CX₁₀CX₆CX₅CXCX₂CX₆CX₅C (SEQID NO: 91), CX₇CX₆CX₃CX₃CX₉C (SEQ ID NO: 92), CX₉CX₈CX₅CX₆CX₅C (SEQ IDNO: 93), CX₁₀CX₂CX₂CX₇CXCX₁₁CX₅C (SEQ ID NO: 94), andCX₁₀CX₆CX₅CXCX₂CX₈CX₄C (SEQ ID NO: 95); and a (X^(a)X^(b))_(z) motif,X^(a) is any amino acid residue, X^(b) is an aromatic amino acidselected from the group consisting of: tyrosine (Y), phenylalanine (F),tryptophan (W), and histidine (H), and wherein z is 1-4.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises: a CX¹X²X³X⁴X⁵ motif, whereinX¹ is threonine (T), glycine (G), alanine (A), serine (S), or valine(V), wherein X² is serine (S), threonine (T), proline (P), isoleucine(I), alanine (A), valine (V), or asparagine (N), wherein X³ is valine(V), alanine (A), threonine (T), or aspartic acid (D), wherein X⁴ ishistidine (H), threonine (T), arginine (R), tyrosine (Y), phenylalanine(F), or leucine (L), and wherein X⁵ is glutamine (Q); a cysteine motifselected from the group consisting of: wherein the cysteine motif isselected from the group consisting of: CCX₃CXCX₃CX₂CCXCX₅CX₉CX₅CXC (SEQID NO: 96), CX₆CX₂CX₅CX₄CCXCX₄CX₆CXC (SEQ ID NO: 97),CX₇CXCX₅CX₄CCCX₄CX₆CXC (SEQ ID NO: 98), CX₉CX₃CXCX₂CXCCCX₆CX₄C (SEQ IDNO: 99), CX₅CX₃CXCX₄CX₄CCX₁₀CX₂CC (SEQ ID NO: 100),CX₅CXCX₁CXCX₃CCX₃CX₄CX₁₀C (SEQ ID NO: 101), CX₉CCCX₃CX₄CCCX₅CX₆C (SEQ IDNO: 102), CCX₈CX₅CX₄CX₃CX₄CCXCX₁C (SEQ ID NO: 103),CCX₆CCX₅CCCX₄CX₄CX₁₂C (SEQ ID NO: 104), CX₆CX₂CX₃CCCX₄CX₅CX₃CX₃C (SEQ IDNO: 105), CX₃CX₅CX₆CX₄CCXCX₅CX₄CXC (SEQ ID NO: 106),CX₄CX₄CCX₄CX₄CXCX₁₁CX₂CXC (SEQ ID NO: 107), CX₅CX₂CCX₅CX₄CCX₃CCX₇C (SEQID NO: 108), CX₅CX₅CX₃CX₂CXCCX₄CX₇CXC (SEQ ID NO: 109),CX₃CX₇CX₃CX₄CCXCX₂CX₅CX₂C (SEQ ID NO: 110), CX₉CX₃CXCX₄CCX₅CCCX₆C (SEQID NO: 111), CX₉CX₃CXCX₂CXCCX₆CX₃CX₃C (SEQ ID NO: 112),CX₈CCXCX₃CCX₃CXCX₃CX₄C (SEQ ID NO: 113), CX₉CCX₄CX₂CXCCXCX₄CX₃C (SEQ IDNO: 114), CX₁₀CXCX₃CX₂CXCCX₄CX₅CXC (SEQ ID NO: 115),CX₉CXCX₃CX₂CXCCX₄CX₅CXC (SEQ ID NO: 116), CX₆CCXCX₅CX₄CCXCX₅CX₂C (SEQ IDNO: 117), CX₆CCXCX₃CXCCX₃CX₄CC (SEQ ID NO: 118), CX₆CCXCX₃CXCX₂CXCX₄CX₈C(SEQ ID NO: 119), CX₄CX₂CCX₃CXCX₄CCX₂CX₃C (SEQ ID NO: 120),CX₃CX₅CX₃CCCX₄CX₉C (SEQ ID NO: 121), CCX₉CX₃CXCCX₃CX₅C (SEQ ID NO: 122),CX₉CX₂CX₃CX₄CCX₄CX₅C (SEQ ID NO: 123), CX₉CX₇CX₄CCXCX₇CX₃C (SEQ ID NO:124), CX₉CX₃CCCX₁₀CX₂CX₃C (SEQ ID NO: 125), CX₃CX₅CX₅CX₄CCX₁₀CX₆C (SEQID NO: 126), CX₉CX₅CX₄CCXCX₅CX₄C (SEQ ID NO: 127), CX₇CXCX₆CX₄CCCX₁₀C(SEQ ID NO: 128), CX₈CX₂CX₄CCX₄CX₃CX₃C (SEQ ID NO: 129),CX₇CX₅CXCX₄CCX₇CX₄C (SEQ ID NO: 130), CX₁₁CX₃CX₄CCCX₈CX₂C (SEQ ID NO:131), CX₂CX₃CX₄CCX₄CX₅CX₁₅C (SEQ ID NO: 132), CX₉CX₅CX₄CCX₇C (SEQ ID NO:133), CX₉CX₇CX₃CX₂CX₆C (SEQ ID NO: 134), CX₉CX₅CX₄CCX₁₄C (SEQ ID NO:135), CX₉CX₅CX₄CCX₈C (SEQ ID NO: 136), CX₉CX₆CX₄CCXC (SEQ ID NO: 137),CX₅CCX₇CX₄CX₁₂ (SEQ ID NO: 138), CX₁₀CX₃CX₄CCX₄C (SEQ ID NO: 139),CX₉CX₄CCX₅CX₄C (SEQ ID NO: 140), CX₁₀CX₃CX₄CX₇CXC (SEQ ID NO: 141),CX₇CX₇CX₂CX₂CX₃C (SEQ ID NO: 142), CX₉CX₄CX₄CCX₆C (SEQ ID NO: 143),CX₇CXCX₃CXCX₆C (SEQ ID NO: 144), CX₇CXCX₄CXCX₄C (SEQ ID NO: 145),CX₉CX₅CX₄C (SEQ ID NO: 146), CX₃CX₆CX₈C (SEQ ID NO: 147), CX₁₀CXCX₄C(SEQ ID NO: 148), CX₁₀CCX₄C (SEQ ID NO: 149), CX₁₅C (SEQ ID NO: 150),CX₁₀C (SEQ ID NO: 151), and CX₉C (SEQ ID NO: 152); and ba(X^(a)X^(b))_(z) motif, wherein X^(a) is any amino acid residue, X^(b)is an aromatic amino acid selected from the group consisting of:tyrosine (Y), phenylalanine (F), tryptophan (W), and histidine (H), andwherein z is 1-4.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 comprises an additional sequence that isa linker.

In some embodiments of each or any of the above or below mentionedembodiments, the linker is linked to a C-terminus, a N-terminus, or bothC-terminus and N-terminus of the non-antibody sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the ultralong CDR3 is a ruminant CDR3.

In some embodiments of each or any of the above or below mentionedembodiments, the ruminant is a cow.

In some embodiments of each or any of the above or below mentionedembodiments, the humanized antibody or binding fragment thereofcomprises a human heavy chain variable region framework sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the humanized antibody or binding fragment thereofcomprises a human heavy chain germline sequence or is a derived from ahuman heavy chain germline sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the humanized antibody or binding fragment thereofcomprises a human heavy chain germline sequence that is a VH4 familymember germline sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the humanized antibody or binding fragment thereofcomprises a VH4-34 germline sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the humanized antibody or binding fragment thereofcomprises a human heavy chain germline sequence that is derived fromVH4-34.

In some embodiments of each or any of the above or below mentionedembodiments, the VH4-34 germline sequence comprises a CDR1 comprising aGly31Asp and Tyr32Lys substitution based on Kabat numbering.

In some embodiments of each or any of the above or below mentionedembodiments, the VH4-34 germline sequence comprises a CDR2 comprising aGlu50Ser substitution based on Kabat numbering.

In some embodiments of each or any of the above or below mentionedembodiments, the VH4-34 germline sequence comprises a CDR1 comprisingAla23Thr, Val24Ala, Tyr25Ser, Gly27Phe, Phe29Leu, Gly31Asp, Tyr32Lys,Tyr33Ala, Trp34Val, and Ser35Gly substitutions, and a CDR2 comprisingIle48Leu, Glu50Ser, Asn52Asp, His53Thr, Ser54Gly, Ser56Asn, and Asn58Glysubstitutions, based on Kabat numbering.

In some embodiments of each or any of the above or below mentionedembodiments, the humanized antibody or binding fragment thereofcomprises the amino acid sequence set forth in SEQ ID NO: 470.

In some embodiments of each or any of the above or below mentionedembodiments, the humanized antibody or binding fragment thereofcomprises the amino acid sequence set forth in SEQ ID NO: 461, 462, 463,464, 465, 466, 467, 468, or 469; and the amino acid sequence set forthin SEQ ID NO: 470.

In some embodiments of each or any of the above or below mentionedembodiments, the humanized antibody or binding fragment thereofcomprises the amino acid sequence set forth in SEQ ID NO: 461, 462, 463,464, 465, 466, 467, 468, or 469; the amino acid sequence set forth inSEQ ID NO: 470; and a peptide sequence, wherein the peptide sequence ispositioned between SEQ ID NO: 461, 462, 463, 464, 465, 466, 467, 468, or469, and SEQ ID NO: 470.

In some embodiments of each or any of the above or below mentionedembodiments, the peptide sequence is a bovine sequence, a non-bovinesequence, an antibody sequence, or a non-antibody sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the humanized antibody or binding fragment thereofcomprises a lambda light chain variable region sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the humanized antibody or binding fragment thereofcomprises a light chain variable region sequence that is a lambda lightchain variable region sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the lambda light chain variable region sequence is a bovinelambda light chain variable region sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the lambda light chain variable region sequence is a humanlambda light chain variable region sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the human lambda light chain variable region sequence isVL1-51.

In some embodiments of each or any of the above or below mentionedembodiments, the human lambda light chain variable region sequence isderived from VL1-51.

In some embodiments of each or any of the above or below mentionedembodiments, the VL1-51 germline sequence comprises a CDR1 comprisingIle29Val and Asn32Gly substitution based on Kabat numbering.

In some embodiments of each or any of the above or below mentionedembodiments, the VL1-51 germline sequence comprises a CDR2 comprising asubstitution of DNN to GDT.

In some embodiments of each or any of the above or below mentionedembodiments, the VL1-51 germline sequence comprises a CDR2 comprising asubstitution of DNNKRP (SEQ ID NO: 471) to GDTSRA (SEQ ID NO: 472).

In some embodiments of each or any of the above or below mentionedembodiments, the VL1-51 germline sequence comprises a S2A, T5N, P8S,A12G, A13S, and P14L substitution based on Kabat numbering.

In some embodiments of each or any of the above or below mentionedembodiments, the VL1-51 germline sequence comprises a S2A, T5N, P8S,A12G, A13S, and P14L substitution based on Kabat numbering, and a CDR2comprising a substitution of DNN to GDT.

In some embodiments of each or any of the above or below mentionedembodiments, the humanized antibody or binding fragment thereofcomprising the amino acid sequence set forth in SEQ ID NO: 440, 441,442, 443, or 444.

In some embodiments of each or any of the above or below mentionedembodiments, the humanized antibodies or binding fragments thereof arepresent in a spatially addressed format.

The present disclosure also provides a method of humanizing an antibodyvariable region comprising the step of genetically combining a nucleicacid sequence encoding a non-human ultralong CDR3 with a nucleic acidsequence encoding a human variable region framework (FR) sequence.

The present disclosure also provides a method of generating a library ofhumanized antibodies that comprises an ultralong CDR3, the methodcomprising: combining a nucleic acid sequence encoding an ultralong CDR3with a nucleic acid sequence encoding a human variable region framework(FR) sequence to produce nucleic acids encoding for humanized antibodiesthat comprises an ultralong CDR3; and expressing the nucleic acidsencoding for humanized antibodies that comprises an ultralong CDR3 togenerate a library of humanized antibodies that comprises an ultralongCDR3.

The present disclosure also provides a method of generating a library ofhumanized antibodies or binding fragments thereof comprising anultralong CDR3 and which comprises a non-antibody sequence, the methodcomprising: combining a nucleic acid sequence encoding an ultralongCDR3, a nucleic acid sequence encoding a human variable region framework(FR) sequence, and a nucleic acid sequence encoding a non-antibodysequence to produce nucleic acids encoding humanized antibodies orbinding fragments thereof comprising an ultralong CDR3 and anon-antibody sequence, and expressing the nucleic acids encodinghumanized antibodies or binding fragments thereof comprising anultralong CDR3 and a non-antibody sequence to generate a library ofhumanized antibodies or binding fragments thereof comprising anultralong CDR3 and a non-antibody sequence. In some embodiments, theultralong CDR3 comprises a bovine, a non-bovine, an antibody, or anon-antibody sequence.

The present disclosure also provides a library of humanized antibodiesor binding fragments thereof comprising an ultralong CDR3 whichcomprises a non-bovine or a non-antibody sequence.

The present disclosure also provides a method of generating a library ofhumanized antibodies or binding fragments thereof comprising anultralong CDR3 which comprises a cysteine motif, the method comprising:combining a human variable region framework (FR) sequence, and a nucleicacid sequence encoding an ultralong CDR3 and a cysteine motif;introducing one or more nucleotide changes to the nucleic acid sequenceencoding one or more amino acid residues that are positioned between oneor more cysteine residues in the cysteine motif for nucleotides encodingdifferent amino acid residues to produce nucleic acids encodinghumanized antibodies or binding fragments thereof comprising anultralong CDR3 and a cysteine motif with one or more nucleotide changesintroduced between one or more cysteine residues in the cysteine domain;and expressing the nucleic acids encoding humanized antibodies orbinding fragments thereof comprising an ultralong CDR3 and a cysteinemotif with one or more nucleotide changes introduced between one or morecysteine residues in the cysteine domain to generate a library ofhumanized antibodies or binding fragments thereof comprising anultralong CDR3 and a cysteine motif with one or more amino acid changesintroduced between one or more cysteine residues in the cysteine domain.

The present disclosure also provides a library of humanized antibodiesor binding fragments thereof comprising an ultralong CDR3 whichcomprises a cysteine motif, wherein the antibodies or binding fragmentscomprise one or more substitutions of amino acid residues that arepositioned between cysteine residues in the cysteine motif.

The present disclosure also provides a method of generating a library ofhumanized antibodies or binding fragments thereof comprising a bovineultralong CDR3, the method comprising: combining a nucleic acid sequenceencoding a human variable region framework (FR) sequence and a nucleicacid encoding a bovine ultralong CDR3, and expressing the nucleic acidsencoding a human variable region framework (FR) sequence and a nucleicacid encoding a bovine ultralong CDR3 to generate a library of humanizedantibodies or binding fragments thereof comprising a bovine ultralongCDR3.

The present disclosure provides humanized antibodies, includingantibodies comprising a CDR3 scaffold, methods of making same, and usesthereof.

The present disclosure provides a humanized antibody or binding fragmentthereof comprising a CDR3 scaffold.

In some embodiments, the CDR3 scaffold comprises one or more humanvariable region framework sequences.

The present disclosure also provides a library of humanized antibodiesor binding fragments thereof comprising a bovine ultralong CDR3.

In some embodiments of each or any of the above or below mentionedembodiments, the CDR3 scaffold comprises a X¹X²X³X⁴X⁵ motif, wherein X¹is threonine (T), glycine (G), alanine (A), serine (S), or valine (V),wherein X² is serine (S), threonine (T), proline (P), isoleucine (I),alanine (A), valine (V), or asparagine (N), wherein X³ is valine (V),alanine (A), threonine (T), or aspartic acid (D), wherein X⁴ ishistidine (H), threonine (T), arginine (R), tyrosine (Y), phenylalanine(F), or leucine (L), and wherein X⁵ is glutamine (Q).

In some embodiments of each or any of the above or below mentionedembodiments, the CDR3 scaffold is 35 amino acids in length or longer, 40amino acids in length or longer, 45 amino acids in length or longer, 50amino acids in length or longer, 55 amino acids in length or longer, or60 amino acids in length or longer.

In some embodiments of each or any of the above or below mentionedembodiments, the CDR3 scaffold is 35 amino acids in length or longer.

In some embodiments of each or any of the above or below mentionedembodiments, the CDR3 scaffold comprises 3 or more cysteine residues, 4or more cysteine residues, 5 or more cysteine residues, 6 or morecysteine residues, 7 or more cysteine residues, 8 or more cysteineresidues, 9 or more cysteine residues, 10 or more cysteine residues, 11or more cysteine residues, or 12 or more cysteine residues.

In some embodiments of each or any of the above or below mentionedembodiments, the CDR3 scaffold comprises 3 or more cysteine residues.

In some embodiments of each or any of the above or below mentionedembodiments, the CDR3 scaffold comprises a cysteine motif.

In some embodiments of each or any of the above or below mentionedembodiments, the cysteine motif is selected from the group consistingof:

(SEQ ID NO: 41) CX₁₀CX₅CX₅CXCX₇C,  (SEQ ID NO: 42) CX₁₀CX₆CX₅CXCX₁₅C,(SEQ ID NO: 43) CX₁₁CXCX₅C,  (SEQ ID NO: 44) CX₁₁CX₅CX₅CXCX₇C,(SEQ ID NO: 45) CX₁₀CX₆CX₅CXCX₁₃C, (SEQ ID NO: 46) CX₁₀CX₅CXCX₄CX₈C,(SEQ ID NO: 47) CX₁₀CX₆CX₆CXCX₇C,  (SEQ ID NO: 48) CX₁₀CX₄CX₇CXCX₈C,(SEQ ID NO: 49) CX₁₀CX₄CX₇CXCX₇C, (SEQ ID NO: 50) CX₁₃CX₈CX₈C,(SEQ ID NO: 51) CX₁₀CX₆CX₅CXCX₇C, (SEQ ID NO: 52) CX₁₀CX₅CX₅C,(SEQ ID NO: 53) CX₁₀CX₅CX₆CXCX₇C,  (SEQ ID NO: 54) CX₁₀CX₆CX₅CX₇CX₈C,(SEQ ID NO: 55) CX₉CX₇CX₅CXCX₇C,  (SEQ ID NO: 56) CX₁₀CX₆CX₅CXCX₈C,(SEQ ID NO: 57) CX₁₀CXCX₄CX₅CX₁₁C,  (SEQ ID NO: 58)CX₇CX₃CX₆CX₅CXCX₅CX₁₀C, (SEQ ID NO: 59) CX₁₀CXCX₄CX₅CXCX₂CX₃C, (SEQ ID NO: 60) CX₁₆CX₅CXC, (SEQ ID NO: 61) CX₆CX₄CXCX₄CX₅C, (SEQ ID NO: 62) CX₁₁CX₄CX₅CX₆CX₃C, (SEQ ID NO: 63) CX₈CX₂CX₆CX₅C,(SEQ ID NO: 64) CX₁₀CX₅CX₅CXCX₁₀C, (SEQ ID NO: 65) CX₁₀CXCX₆CX₄CXC, (SEQ ID NO: 66) CX₁₀CX₅CX₅CXCX₂C, (SEQ ID NO: 67) CX₁₄CX₂CX₃CXCXC,(SEQ ID NO: 68) CX₁₅CX₅CXC, (SEQ ID NO: 69) CX₄CX₆CX₈CX₂CX₁₁C, (SEQ ID NO: 70) CX₆CX₄CX₅CX₅CX₁₂C, (SEQ ID NO: 71)CX₇CX₃CXCXCX₄CX₅CX₉C,  (SEQ ID NO: 72) CX₁₀CX₆CX₅C, (SEQ ID NO: 73)CX₇CX₃CX₅CX₅CX₉C,  (SEQ ID NO: 74) CX₇CX₅CXCX₂C,  (SEQ ID NO: 75)CX₁₀CXCX₆C,  (SEQ ID NO: 76) CX₁₀CX₃CX₃CX₅CX₇CXCX₆C,  (SEQ ID NO: 77)CX₁₀CX₄CX₅CX₁₂CX₂C,  (SEQ ID NO: 78) CX₁₂CX₄CX₅CXCXCX₉CX₃C, (SEQ ID NO: 79) CX₁₂CX₄CX₅CX₁₂CX₂C,  (SEQ ID NO: 80) CX₁₀CX₆CX₅CXCX₁₁C, (SEQ ID NO: 81) CX₁₆CX₅CXCXCX₁₄C,  (SEQ ID NO: 82) CX₁₀CX₅CXCX₈CX₆C, (SEQ ID NO: 83) CX₁₂CX₄CX₅CX₈CX₂C, (SEQ ID NO: 84) CX₁₂CX₅CX₅CXCX₈C, (SEQ ID NO: 85) CX₁₀CX₆CX₅CXCX₄CXCX₉C, (SEQ ID NO: 86)CX₁₁CX₄CX₅CX₈CX₂C,  (SEQ ID NO: 87) CX₁₀CX₆CX₅CX₈CX₂C, (SEQ ID NO: 88)CX₁₀CX₆CX₅CXCX₈C,  (SEQ ID NO: 89) CX₁₀CX₆CX₅CXCX₃CX₈CX₂C,(SEQ ID NO: 90) CX₁₀CX₆CX₅CX₃CX₈C,  (SEQ ID NO: 91)CX₁₀CX₆CX₅CXCX₂CX₆CX₅C, (SEQ ID NO: 92) CX₇CX₆CX₃CX₃CX₉C, (SEQ ID NO: 93) CX₉CX₈CX₅CX₆CX₅C, (SEQ ID NO: 94)CX₁₀CX₂CX₂CX₇CXCX₁₁CX₅C,  and  (SEQ ID NO: 95) CX₁₀CX₆CX₅CXCX₂CX₈CX₄C.

In some embodiments of each or any of the above or below mentionedembodiments, the cysteine motif is selected from the group consistingof:

(SEQ ID NO: 96) CCX₃CXCX₃CX₂CCXCX₅CX₉CX₅CXC, (SEQ ID NO: 97)CX₆CX₂CX₅CX₄CCXCX₄CX₆CXC, (SEQ ID NO: 98) CX₇CXCX₅CX₄CCCX₄CX₆CXC,(SEQ ID NO: 99) CX₉CX₃CXCX₂CXCCCX₆CX₄C, (SEQ ID NO: 100)CX₅CX₃CXCX₄CX₄CCX₁₀CX₂CC, (SEQ ID NO: 101) CX₅CXCX₁CXCX₃CCX₃CX₄CX₁₀C,(SEQ ID NO: 102) CX₉CCCX₃CX₄CCCX₅CX₆C, (SEQ ID NO: 103)CCX₈CX₅CX₄CX₃CX₄CCXCX₁C, (SEQ ID NO: 104) CCX₆CCX₅CCCX₄CX₄CX₁₂C,(SEQ ID NO: 105) CX₆CX₂CX₃CCCX₄CX₅CX₃CX₃C, (SEQ ID NO: 106)CX₃CX₅CX₆CX₄CCXCX₅CX₄CXC, (SEQ ID NO: 107) CX₄CX₄CCX₄CX₄CXCX₁₁CX₂CXC,(SEQ ID NO: 108) CX₅CX₂CCX₅CX₄CCX₃CCX₇C, (SEQ ID NO: 109)CX₅CX₅CX₃CX₂CXCCX₄CX₇CXC, (SEQ ID NO: 110) CX₃CX₇CX₃CX₄CCXCX₂CX₅CX₂C,(SEQ ID NO: 111) CX₉CX₃CXCX₄CCX₅CCCX₆C, (SEQ ID NO: 112)CX₉CX₃CXCX₂CXCCX₆CX₃CX₃C, (SEQ ID NO: 113) CX₈CCXCX₃CCX₃CXCX₃CX₄C,(SEQ ID NO: 114) CX₉CCX₄CX₂CXCCXCX₄CX₃C, (SEQ ID NO: 115)CX₁₀CXCX₃CX₂CXCCX₄CX₅CXC, (SEQ ID NO: 116) CX₉CXCX₃CX₂CXCCX₄CX₅CXC,(SEQ ID NO: 117) CX₆CCXCX₅CX₄CCXCX₅CX₂C, (SEQ ID NO: 118)CX₆CCXCX₃CXCCX₃CX₄CC, (SEQ ID NO: 119) CX₆CCXCX₃CXCX₂CXCX₄CX₈C,(SEQ ID NO: 120) CX₄CX₂CCX₃CXCX₄CCX₂CX₃C, (SEQ ID NO: 121)CX₃CX₅CX₃CCCX₄CX₉C, (SEQ ID NO: 122) CCX₉CX₃CXCCX₃CX₅C, (SEQ ID NO: 123)CX₉CX₂CX₃CX₄CCX₄CX₅C, (SEQ ID NO: 124) CX₉CX₇CX₄CCXCX₇CX₃C,(SEQ ID NO: 125) CX₉CX₃CCCX₁₀CX₂CX₃C, (SEQ ID NO: 126)CX₃CX₅CX₅CX₄CCX₁₀CX₆C, (SEQ ID NO: 127) CX₉CX₅CX₄CCXCX₅CX₄C,(SEQ ID NO: 128) CX₇CXCX₆CX₄CCCX₁₀C, (SEQ ID NO: 129)CX₈CX₂CX₄CCX₄CX₃CX₃C, (SEQ ID NO: 130) CX₇CX₅CXCX₄CCX₇CX₄C,(SEQ ID NO: 131) CX₁₁CX₃CX₄CCCX₈CX₂C, (SEQ ID NO: 132)CX₂CX₃CX₄CCX₄CX₅CX₁₅C, (SEQ ID NO: 133) CX₉CX₅CX₄CCX₇C, (SEQ ID NO: 134)CX₉CX₇CX₃CX₂CX₆C, (SEQ ID NO: 135) CX₉CX₅CX₄CCX₁₄C, (SEQ ID NO: 136)CX₉CX₅CX₄CCX₈C, (SEQ ID NO: 137) CX₉CX₆CX₄CCXC, (SEQ ID NO: 138)CX₅CCX₇CX₄CX₁₂, (SEQ ID NO: 139) CX₁₀CX₃CX₄CCX₄C, (SEQ ID NO: 140)CX₉CX₄CCX₅CX₄C, (SEQ ID NO: 141) CX₁₀CX₃CX₄CX₇CXC, (SEQ ID NO: 142)CX₇CX₇CX₂CX₂CX₃C, (SEQ ID NO: 143) CX₉CX₄CX₄CCX₆C, (SEQ ID NO: 144)CX₇CXCX₃CXCX₆C, (SEQ ID NO: 145) CX₇CXCX₄CXCX₄C, (SEQ ID NO: 146)CX₉CX₅CX₄C, (SEQ ID NO: 147) CX₃CX₆CX₉C, (SEQ ID NO: 148) CX₁₉CXCX₄C,(SEQ ID NO: 149) CX₁₀CCX₄C, (SEQ ID NO: 150) CX₁₅C,  (SEQ ID NO: 151)CX₁₀C, and (SEQ ID NO: 152) CX₉C.

In some embodiments of each or any of the above or below mentionedembodiments, the CDR3 scaffold comprises 2 to 6 disulfide bonds.

In some embodiments of each or any of the above or below mentionedembodiments, the X¹X²X³X⁴X⁵ motif in the CDR3 scaffold is TTVHQ (SEQ IDNO: 153), TSVHQ (SEQ ID NO: 154), SSVTQ (SEQ ID NO: 155), STVHQ (SEQ IDNO: 156), ATVRQ (SEQ ID NO: 157), TTVYQ (SEQ ID NO: 158), SPVHQ (SEQ IDNO: 159), ATVYQ (SEQ ID NO: 160), TAVYQ (SEQ ID NO: 161), TNVHQ (SEQ IDNO: 162), ATVHQ (SEQ ID NO: 163), STVYQ (SEQ ID NO: 164), TIVHQ (SEQ IDNO: 165), AIVYQ (SEQ ID NO: 166), TTVFQ (SEQ ID NO: 167), AAVFQ (SEQ IDNO: 168), GTVHQ (SEQ ID NO: 169), ASVHQ (SEQ ID NO: 170), TAVFQ (SEQ IDNO: 171), ATVFQ (SEQ ID NO: 172), AAAHQ (SEQ ID NO: 173), VVVYQ (SEQ IDNO: 174), GTVFQ (SEQ ID NO: 175), TAVHQ (SEQ ID NO: 176), ITVHQ (SEQ IDNO: 177), ITAHQ (SEQ ID NO: 178), VTVHQ (SEQ ID NO: 179); AAVHQ (SEQ IDNO: 180), GTVYQ (SEQ ID NO: 181), TTVLQ (SEQ ID NO: 182), TTTHQ (SEQ IDNO: 183), or TTDYQ (SEQ ID NO: 184).

In some embodiments of each or any of the above or below mentionedembodiments, the CDR3 scaffold comprises a CX¹X²X³X⁴X⁵ motif.

In some embodiments of each or any of the above or below mentionedembodiments, the CX¹X²X³X⁴X⁵ motif is CTTVHQ (SEQ ID NO: 185), CTSVHQ(SEQ ID NO: 186), CSSVTQ (SEQ ID NO: 187), CSTVHQ (SEQ ID NO: 188),CATVRQ (SEQ ID NO: 189), CTTVYQ (SEQ ID NO: 190), CSPVHQ (SEQ ID NO:191), CATVYQ (SEQ ID NO: 192), CTAVYQ (SEQ ID NO: 193), CTNVHQ (SEQ IDNO: 194), CATVHQ (SEQ ID NO: 195), CSTVYQ (SEQ ID NO: 196), CTIVHQ (SEQID NO: 197), CAIVYQ (SEQ ID NO: 198), CTTVFQ (SEQ ID NO: 199), CAAVFQ(SEQ ID NO: 200), CGTVHQ (SEQ ID NO: 201), CASVHQ (SEQ ID NO: 202),CTAVFQ (SEQ ID NO: 203), CATVFQ (SEQ ID NO: 204), CAAAHQ (SEQ ID NO:205), CVVVYQ (SEQ ID NO: 206), CGTVFQ (SEQ ID NO: 207), CTAVHQ (SEQ IDNO: 208), CITVHQ (SEQ ID NO: 209), CITAHQ (SEQ ID NO: 210), CVTVHQ (SEQID NO: 211); CAAVHQ (SEQ ID NO: 212), CGTVYQ (SEQ ID NO: 213), CTTVLQ(SEQ ID NO: 214), CTTTHQ (SEQ ID NO: 215), or CTTDYQ (SEQ ID NO: 216).

In some embodiments of each or any of the above or below mentionedembodiments, the CDR3 scaffold comprises a (X^(a)X^(b))_(z) motif,wherein X^(a) is any amino acid residue, X^(b) is an aromatic amino acidselected from the group consisting of: tyrosine (Y), phenylalanine (F),tryptophan (W), and histidine (H), and wherein z is 1-4.

In some embodiments of each or any of the above or below mentionedembodiments, the (X^(a)X^(b))_(z) motif is CYTYNYEF (SEQ ID NO: 217),HYTYTYDF (SEQ ID NO: 218), HYTYTYEW (SEQ ID NO: 219), KHRYTYEW (SEQ IDNO: 220), NYIYKYSF (SEQ ID NO: 221), PYIYTYQF (SEQ ID NO: 222), SFTYTYEW(SEQ ID NO: 223), SYIYIYQW (SEQ ID NO: 224), SYNYTYSW (SEQ ID NO: 225),SYSYSYEY (SEQ ID NO: 226), SYTYNYDF (SEQ ID NO: 227), SYTYNYEW (SEQ IDNO: 228), SYTYNYQF (SEQ ID NO: 229), SYVWTHNF (SEQ ID NO: 230), TYKYVYEW(SEQ ID NO: 231), TYTYTYEF (SEQ ID NO: 232), TYTYTYEW (SEQ ID NO: 233),VFTYTYEF (SEQ ID NO: 234), AYTYEW (SEQ ID NO: 235), DYIYTY (SEQ ID NO:236), IHSYEF (SEQ ID NO: 237), SFTYEF (SEQ ID NO: 238), SHSYEF (SEQ IDNO: 239), THTYEF (SEQ ID NO: 240), TWTYEF (SEQ ID NO: 241), TYNYEW (SEQID NO: 242), TYSYEF (SEQ ID NO: 243), TYSYEH (SEQ ID NO: 244), TYTYDF(SEQ ID NO: 245), TYTYEF (SEQ ID NO: 246), TYTYEW (SEQ ID NO: 247), AYEF(SEQ ID NO: 248), AYSF (SEQ ID NO: 249), AYSY (SEQ ID NO: 250), CYSF(SEQ ID NO: 251), DYTY (SEQ ID NO: 252), KYEH (SEQ ID NO: 253), KYEW(SEQ ID NO: 254), MYEF (SEQ ID NO: 255), NWIY (SEQ ID NO: 256), NYDY(SEQ ID NO: 257), NYQW (SEQ ID NO: 258), NYSF (SEQ ID NO: 259), PYEW(SEQ ID NO: 260), RYNW (SEQ ID NO: 261), RYTY (SEQ ID NO: 262), SYEF(SEQ ID NO: 263), SYEH (SEQ ID NO: 264), SYEW (SEQ ID NO: 265), SYKW(SEQ ID NO: 266), SYTY (SEQ ID NO: 267), TYDF (SEQ ID NO: 268), TYEF(SEQ ID NO: 269), TYEW (SEQ ID NO: 270), TYQW (SEQ ID NO: 271), TYTY(SEQ ID NO: 272), or VYEW (SEQ ID NO: 273).

In some embodiments of each or any of the above or below mentionedembodiments, the (X^(a)X^(b))_(z) motif is YXYXYX.

In some embodiments of each or any of the above or below mentionedembodiments, the CDR3 scaffold comprises a X¹X²X³X⁴X⁵X_(n) motif,wherein X¹ is threonine (T), glycine (G), alanine (A), serine (S), orvaline (V), wherein X² is serine (S), threonine (T), proline (P),isoleucine (I), alanine (A), valine (V), or asparagine (N), wherein X³is valine (V), alanine (A), threonine (T), or aspartic acid (D), whereinX⁴ is histidine (H), threonine (T), arginine (R), tyrosine (Y),phenylalanine (F), or leucine (L), and wherein X⁵ is glutamine (Q), andwherein n is 27-54.

In some embodiments of each or any of the above or below mentionedembodiments, the CDR3 scaffold comprises X_(n)(X^(a)X^(b))_(z) motif,wherein X^(a) is any amino acid residue, X^(b) is an aromatic amino acidselected from the group consisting of: tyrosine (Y), phenylalanine (F),tryptophan (W), and histidine (H), wherein n is 27-54, and wherein z is1-4.

In some embodiments of each or any of the above or below mentionedembodiments, the CDR3 scaffold comprises aX¹X²X³X⁴X⁵X_(n)(X^(a)X^(b))_(z) motif, herein X₁ is threonine (T),glycine (G), alanine (A), serine (S), or valine (V), wherein X₂ isserine (S), threonine (T), proline (P), isoleucine (I), alanine (A),valine (V), or asparagine (N), wherein X₃ is valine (V), alanine (A),threonine (T), or aspartic acid (D), wherein X₄ is histidine (H),threonine (T), arginine (R), tyrosine (Y), phenylalanine (F), or leucine(L), wherein X₅ is glutamine (Q), X^(a) is any amino acid residue, X^(b)is an aromatic amino acid selected from the group consisting of:tyrosine (Y), phenylalanine (F), tryptophan (W), and histidine (H),wherein n is 27-54, and wherein z is 1-4.

In some embodiments of each or any of the above or below mentionedembodiments, the X¹X²X³X⁴X⁵ motif in the CDR3 scaffold is TTVHQ (SEQ IDNO: 153) or TSVHQ (SEQ ID NO: 154), and wherein the (X^(a)X^(b))_(z)motif is YXYXYX.

In some embodiments of each or any of the above or below mentionedembodiments, the CDR3 scaffold comprises: a CX¹X²X³X⁴X⁵ motif, whereinX¹ is threonine (T), glycine (G), alanine (A), serine (S), or valine(V), wherein X² is serine (S), threonine (T), proline (P), isoleucine(I), alanine (A), valine (V), or asparagine (N), wherein X³ is valine(V), alanine (A), threonine (T), or aspartic acid (D), wherein X⁴ ishistidine (H), threonine (T), arginine (R), tyrosine (Y), phenylalanine(F), or leucine (L), and wherein X⁵ is glutamine (Q), a cysteine motifselected from the group consisting of: CX₁₀CX₅CX₅CXCX₇C (SEQ ID NO: 41),CX₁₀CX₆CX₅CXCX₁₅C (SEQ ID NO: 42), CX₁₁CXCX₅C (SEQ ID NO: 43),CX₁₁CX₅CX₅CXCX₇C (SEQ ID NO: 44), CX₁₀CX₆CX₅CXCX₁₃C (SEQ ID NO: 45),CX₁₀CX₅CXCX₄CX₈C (SEQ ID NO: 46), CX₁₀CX₆CX₆CXCX₇C (SEQ ID NO: 47),CX₁₀CX₄CX₇CXCX₈C (SEQ ID NO: 48), CX₁₀CX₄CX₇CXCX₇C (SEQ ID NO: 49),CX₁₃CX₈CX₈C (SEQ ID NO: 50), CX₁₀CX₆CX₅CXCX₇C (SEQ ID NO: 51),CX₁₀CX₅CX₅C (SEQ ID NO: 52), CX₁₀CX₅CX₆CXCX₇C (SEQ ID NO: 53),CX₁₀CX₆CX₅CX₇CX₉C (SEQ ID NO: 54), CX₉CX₇CX₅CXCX₇C (SEQ ID NO: 55),CX₁₀CX₆CX₅CXCX₉C (SEQ ID NO: 56), CX₁₀CXCX₄CX₅CX₁₁C (SEQ ID NO: 57),CX₇CX₃CX₆CX₅CXCX₅CX₁₀C (SEQ ID NO: 58), CX₁₀CXCX₄CX₅CXCX₂CX₃C (SEQ IDNO: 59), CX₁₆CX₅CXC (SEQ ID NO: 60), CX₆CX₄CXCX₄CX₅C (SEQ ID NO: 61),CX₁₁CX₄CX₅CX₆CX₃C (SEQ ID NO: 62), CX₈CX₂CX₆CX₅C (SEQ ID NO: 63),CX₁₀CX₅CX₅CXCX₁₀C (SEQ ID NO: 64), CX₁₀CXCX₆CX₄CXC (SEQ ID NO: 65),CX₁₀CX₅CX₅CXCX₂C (SEQ ID NO: 66), CX₁₄CX₂CX₃CXCXC (SEQ ID NO: 67),CX₁₅CX₅CXC (SEQ ID NO: 68), CX₄CX₆CX₉CX₂CX₁₁C (SEQ ID NO: 69),CX₆CX₄CX₅CX₅CX₁₂C (SEQ ID NO: 70), CX₇CX₃CXCXCX₄CX₅CX₉C (SEQ ID NO: 71),CX₁₀CX₆CX₅C (SEQ ID NO: 72), CX₇CX₃CX₅CX₅CX₉C (SEQ ID NO: 73),CX₇CX₅CXCX₂C (SEQ ID NO: 74), CX₁₀CXCX₆C (SEQ ID NO: 75),CX₁₀CX₃CX₃CX₅CX₇CXCX₆C (SEQ ID NO: 76), CX₁₀CX₄CX₅CX₁₂CX₂C (SEQ ID NO:77), CX₁₂CX₄CX₅CXCXCX₉CX₃C (SEQ ID NO: 78), CX₁₂CX₄CX₅CX₁₂CX₂C (SEQ IDNO: 79), CX₁₀CX₆CX₅CXCX₁₁C (SEQ ID NO: 80), CX₁₆CX₅CXCXCX₁₄C (SEQ ID NO:81), CX₁₀CX₅CXCX₈CX₆C (SEQ ID NO: 82), CX₁₂CX₄CX₅CX₈CX₂C (SEQ ID NO:83), CX₁₂CX₅CX₅CXCX₈C (SEQ ID NO: 84), CX₁₀CX₆CX₅CXCX₄CXCX₉C (SEQ ID NO:85), CX₁₁CX₄CX₅CX₈CX₂C (SEQ ID NO: 86), CX₁₀CX₆CX₅CX₈CX₂C (SEQ ID NO:87), CX₁₀CX₆CX₅CXCX₈C (SEQ ID NO: 88), CX₁₀CX₆CX₅CXCX₃CX₈CX₂C (SEQ IDNO: 89), CX₁₀CX₆CX₅CX₃CX₈C (SEQ ID NO: 90), CX₁₀CX₆CX₅CXCX₂CX₆CX₅C (SEQID NO: 91), CX₇CX₆CX₃CX₃CX₉C (SEQ ID NO: 92), CX₉CX₈CX₅CX₆CX₅C (SEQ IDNO: 93), CX₁₀CX₂CX₂CX₇CXCX₁₁CX₅C (SEQ ID NO: 94), andCX₁₀CX₆CX₅CXCX₂CX₈CX₄C (SEQ ID NO: 95); and (X^(a)X^(b))_(z) motif,wherein X^(a) is any amino acid residue, X^(b) is an aromatic amino acidselected from the group consisting of: tyrosine (Y), phenylalanine (F),tryptophan (W), and histidine (H), and wherein z is 1-4.

In some embodiments of each or any of the above or below mentionedembodiments, the CDR3 scaffold comprises: a CX¹X²X³X⁴X⁵ motif, whereinX¹ is threonine (T), glycine (G), alanine (A), serine (S), or valine(V), wherein X² is serine (S), threonine (T), proline (P), isoleucine(I), alanine (A), valine (V), or asparagine (N), wherein X³ is valine(V), alanine (A), threonine (T), or aspartic acid (D), wherein X⁴ ishistidine (H), threonine (T), arginine (R), tyrosine (Y), phenylalanine(F), or leucine (L), and wherein X⁵ is glutamine (Q); a cysteine motifselected from the group consisting of: wherein the cysteine motif isselected from the group consisting of: CCX₃CXCX₃CX₂CCXCX₅CX₉CX₅CXC (SEQID NO: 96), CX₆CX₂CX₅CX₄CCXCX₄CX₆CXC (SEQ ID NO: 97),CX₇CXCX₅CX₄CCCX₄CX₆CXC (SEQ ID NO: 98), CX₉CX₃CXCX₂CXCCCX₆CX₄C (SEQ IDNO: 99), CX₅CX₃CXCX₄CX₄CCX₁₀CX₂CC (SEQ ID NO: 100),CX₅CXCX₁CXCX₃CCX₃CX₄CX₁₀C (SEQ ID NO: 101), CX₉CCCX₃CX₄CCCX₅CX₆C (SEQ IDNO: 102), CCX₈CX₅CX₄CX₃CX₄CCXCX₁C (SEQ ID NO: 103),CCX₆CCX₅CCCX₄CX₄CX₁₂C (SEQ ID NO: 104), CX₆CX₂CX₃CCCX₄CX₅CX₃CX₃C (SEQ IDNO: 105), CX₃CX₅CX₆CX₄CCXCX₅CX₄CXC (SEQ ID NO: 106),CX₄CX₄CCX₄CX₄CXCX₁₁CX₂CXC (SEQ ID NO: 107), CX₅CX₂CCX₅CX₄CCX₃CCX₇C (SEQID NO: 108), CX₅CX₅CX₃CX₂CXCCX₄CX₇CXC (SEQ ID NO: 109),CX₃CX₇CX₃CX₄CCXCX₂CX₅CX₂C (SEQ ID NO: 110), CX₉CX₃CXCX₄CCX₅CCCX₆C (SEQID NO: 111), CX₉CX₃CXCX₂CXCCX₆CX₃CX₃C (SEQ ID NO: 112),CX₈CCXCX₃CCX₃CXCX₃CX₄C (SEQ ID NO: 113), CX₉CCX₄CX₂CXCCXCX₄CX₃C (SEQ IDNO: 114), CX₁₀CXCX₃CX₂CXCCX₄CX₅CXC (SEQ ID NO: 115),CX₉CXCX₃CX₂CXCCX₄CX₅CXC (SEQ ID NO: 116), CX₆CCXCX₅CX₄CCXCX₅CX₂C (SEQ IDNO: 117), CX₆CCXCX₃CXCCX₃CX₄CC (SEQ ID NO: 118), CX₆CCXCX₃CXCX₂CXCX₄CX₈C(SEQ ID NO: 119), CX₄CX₂CCX₃CXCX₄CCX₂CX₃C (SEQ ID NO: 120),CX₃CX₅CX₃CCCX₄CX₉C (SEQ ID NO: 121), CCX₉CX₃CXCCX₃CX₅C (SEQ ID NO: 122),CX₉CX₂CX₃CX₄CCX₄CX₅C (SEQ ID NO: 123), CX₉CX₇CX₄CCXCX₇CX₃C (SEQ ID NO:124), CX₉CX₃CCCX₁₀CX₂CX₃C (SEQ ID NO: 125), CX₃CX₅CX₅CX₄CCX₁₀CX₆C (SEQID NO: 126), CX₉CX₅CX₄CCXCX₅CX₄C (SEQ ID NO: 127), CX₇CXCX₆CX₄CCCX₁₀C(SEQ ID NO: 128), CX₈CX₂CX₄CCX₄CX₃CX₃C (SEQ ID NO: 129),CX₇CX₅CXCX₄CCX₇CX₄C (SEQ ID NO: 130), CX₁₁CX₃CX₄CCCX₈CX₂C (SEQ ID NO:131), CX₂CX₃CX₄CCX₄CX₅CX₁₅C (SEQ ID NO: 132), CX₉CX₅CX₄CCX₇C (SEQ ID NO:133), CX₉CX₇CX₃CX₂CX₆C (SEQ ID NO: 134), CX₉CX₅CX₄CCX₁₄C (SEQ ID NO:135), CX₉CX₅CX₄CCX₈C (SEQ ID NO: 136), CX₉CX₆CX₄CCXC (SEQ ID NO: 137),CX₅CCX₇CX₄CX₁₂ (SEQ ID NO: 138), CX₁₀CX₃CX₄CCX₄C (SEQ ID NO: 139),CX₉CX₄CCX₅CX₄C (SEQ ID NO: 140), CX₁₀CX₃CX₄CX₇CXC (SEQ ID NO: 141),CX₇CX₇CX₂CX₂CX₃C (SEQ ID NO: 142), CX₉CX₄CX₄CCX₆C (SEQ ID NO: 143),CX₇CXCX₃CXCX₆C (SEQ ID NO: 144), CX₇CXCX₄CXCX₄C (SEQ ID NO: 145),CX₉CX₅CX₄C (SEQ ID NO: 146), CX₃CX₆CX₈C (SEQ ID NO: 147), CX₁₀CXCX₄C(SEQ ID NO: 148), CX₁₀CCX₄C (SEQ ID NO: 149), CX₁₅C (SEQ ID NO: 150),CX₁₀C (SEQ ID NO: 151), and CX₉C (SEQ ID NO: 152); and a(X^(a)X^(b))_(z) motif, wherein X^(a) is any amino acid residue, X^(b)is an aromatic amino acid selected from the group consisting of:tyrosine (Y), phenylalanine (F), tryptophan (W), and histidine (H), andwherein z is 1-4.

In some embodiments of each or any of the above or below mentionedembodiments, the CDR3 scaffold comprises SEQ ID NO: 40 or a derivativethereof.

In some embodiments of each or any of the above or below mentionedembodiments, the CDR3 scaffold comprises amino acid residues 3-6 of anyof one SEQ ID NO: 1-4.

In some embodiments of each or any of the above or below mentionedembodiments, the CDR3 scaffold comprises a non-human DH or a derivativethereof.

In some embodiments of each or any of the above or below mentionedembodiments, the non-human DH is SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO:7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, or SEQ IDNO: 12

In some embodiments of each or any of the above or below mentionedembodiments, the CDR3 scaffold comprises a JH sequence or a derivativethereof.

In some embodiments of each or any of the above or below mentionedembodiments, the JH sequence is SEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO:15, SEQ ID NO: 16, or SEQ ID NO: 17.

In some embodiments of each or any of the above or below mentionedembodiments, the CDR3 scaffold comprises: a non-human VH sequence or aderivative thereof; a non-human DH sequence or a derivative thereof;and/or a JH sequence or derivative thereof.

In some embodiments of each or any of the above or below mentionedembodiments, the CDR3 scaffold comprises an additional amino acidsequence comprising two to six amino acid residues or more positionedbetween the VH sequence and the DH sequence.

In some embodiments of each or any of the above or below mentionedembodiments, the additional amino acid sequence is selected from thegroup consisting of: IR, IF, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20or SEQ ID NO: 21.

In some embodiments of each or any of the above or below mentionedembodiments, the CDR3 scaffold comprises a sequence derived from orbased on SEQ ID NO: 22, SEQ ID NO: 23, SEQ ID NO: 24, SEQ ID NO: 25, SEQID NO: 26, SEQ ID NO: 27, or SEQ ID NO: 28.

In some embodiments of each or any of the above or below mentionedembodiments, the CDR3 scaffold is a ruminant CDR3 scaffold.

In some embodiments of each or any of the above or below mentionedembodiments, the ruminant is a cow.

The present disclosure also provides a library comprising the CDR3scaffold disclosed herein.

The present disclosure also provides a polynucleotide encoding the CDR3scaffold disclosed herein.

The present disclosure also provides a vector comprising any of thepolynucleotides disclosed herein.

The present disclosure also provides a host cell comprising any of thevectors disclosed herein.

The present disclosure also provides

In some embodiments of each or any of the above or below mentionedembodiments, the cell is a bacteria, virus, or bacteriophage.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description ofthe disclosure, will be better understood when read in conjunction withthe appended figures. For the purpose of illustrating the disclosure,shown in the figures are embodiments which are presently preferred. Itshould be understood, however, that the disclosure is not limited to theprecise arrangements, examples and instrumentalities shown.

FIG. 1 shows a sequence alignment of exemplary bovine-derived antibodyvariable region sequences designated BLV1H12, BLV5B8, BLV5D3, BLV8C11,BF4E9, BF1H1, or F18 that comprise an ultralong CDR3 sequence.

FIG. 2A-C depicts ultralong CDR3 sequences. (Top) Translation from thegermline V_(H)BUL, D_(H)2, and J_(H). The 5 full length ultralong CDRH3s reported in the literature contain between four and eight cysteinesand are not highly homologous to one another; however, some conservationof cysteine residues with D_(H)2 could be found when the first cysteineof these CDR H3s was “fixed” prior to alignment. Four of the sevensequences (BLV1H12, BLV5D3, BLV8C11, and BF4E9) contain four cysteinesin the same positions as D_(H)2, but also have additional cysteines.BLV5B8 has two cysteines in common with the germline D_(H)2. Thislimited homology with some cysteine conservation suggests that mutationof D_(H)2 could generate these sequences. B-L1 and B-L2 are from initialsequences from bovine spleen, and the remaining are selected ultralongCDR H3 sequences from deep sequencing data. The first group contains thelongest CDR H3s identified, and appear clonally related. The * indicatesa sequence represented 167 times, suggesting it was strongly selectedfor function. Several of the eight-cysteine sequences appear selectedfor function as they were represented multiple times, indicated inparentheses. Other representative sequences of various lengths areindicated in the last group. The framework cysteine and tryptophanresidues that define the CDR H3 boundaries are double-underlined. Thesequences BLV1H12 through UL-77 (left-most column) presented in Tables2A-C are depicted broken apart into four segments to identify thesegments of amino acid residues that are derived from certain germlinesequences and V/D/J joining sequences. Moving from left to right, thefirst segment is derived from the V_(H) germline and is represented inthe disclosure as a X¹X²X³X⁴X⁵ motif. The second segment representssequences from V-D joining and is represented in the disclosure asX_(n). The third segment is a string of amino acid residues derived fromD_(H)2 germline, and the fourth segment is a string of amino acidresidues derived from J_(H)1 germline region.

FIG. 3 depicts a sequence alignment of exemplary bovine-derivedultralong CDR3 sequences designated BLV1H12, BLV5B8, BLV5D3, BLV8C11,BF4E9, BF1H1, or F18.

FIG. 4 shows an exemplary bovine germline heavy chain variable region(V_(H)) sequence designated VH-UL suitable for modification or use withan ultralong CDR3 sequence.

FIG. 5A-B shows exemplary human germline heavy chain variable regionsequences designated 4-39, 4-59*03, 4-34*09, and 4-34*02 that aresuitable for modification or use with an ultralong CDR3 sequence (A) andan alignment of these sequences (B).

FIG. 6 shows an exemplary bovine light chain variable region sequencedesignated BLV1H12 suitable for modification or use with an ultralongCDR 3 sequence (e.g., a heavy chain variable region sequence comprisingan ultralong CDR3 sequence).

FIG. 7A-B shows exemplary light chain variable region sequencesdesignated VI1-47, VI1-40*1, VI1-51*01, and VI2-18*02 that are suitablefor modification or use with an ultralong CDR 3 sequence (A) and analignment of these sequences (B).

DETAILED DESCRIPTION

The present disclosure provides humanized antibodies comprisingultralong CDR3 sequences, along with materials for (e.g., proteinsequences, genetic sequences, cells, libraries) and methods of makingthe antibodies (e.g., humanizing methods, library methods). Suchhumanized antibodies may be useful for the treatment or prevention of avariety of disease states or disorders.

The present disclosure also provides humanized antibodies comprisingultralong CDR3 sequences, wherein the CDR3 sequences are 35 amino acidsin length or longer (e.g., 40 or longer, 45 or longer, 50 or longer, 55or longer, 60 or longer) and/or wherein the CDR3 sequences have at least3 cysteine residues or more (e.g., 3 or more cysteine residues, 4 ormore cysteine residues, 5 or more cysteine residues, 6 or more cysteineresidues, 7 or more cysteine residues, 8 or more cysteine residues, 9 ormore cysteine residues, 10 or more cysteine residues, 11 or morecysteine residues, or 12 or more cysteine residues). Such antibodies, asdescribed herein, bind (e.g., specifically or selectively bind) avariety of targets, including, for example protein targets such astransmembrane proteins (e.g., GPCRs, ion channels, transporter, cellsurface receptors).

The present disclosure also provides methods and materials for thepreparation or making of humanized antibodies comprising ultralong CDR3sequences. Such materials include proteins, genetic sequences, cells andlibraries. Such methods include methods of humanization and method ofmaking and screening libraries.

The present disclosure provides a humanized antibody or binding fragmentthereof comprising an ultralong CDR3. In some embodiments, the ultralongCDR3 may be 35 amino acids in length or longer, 40 amino acids in lengthor longer, 45 amino acids in length or longer, 50 amino acids in lengthor longer, 55 amino acids in length or longer, or 60 amino acids inlength or longer. In some embodiments, the ultralong CDR3 may comprise 3or more cysteine residues, 4 or more cysteine residues, 5 or morecysteine residues, 6 or more cysteine residues, 7 or more cysteineresidues, 8 or more cysteine residues, 9 or more cysteine residues, 10or more cysteine residues, 11 or more cysteine residues, or 12 or morecysteine residues. The ultralong CDR3 may comprise a cysteine motifincluding, for example, where the cysteine motif is selected from thegroup consisting of:

(SEQ ID NO: 41) CX₁₀CX₅CX₅CXCX₇C,  (SEQ ID NO: 42) CX₁₀CX₆CX₅CXCX₁₅C, (SEQ ID NO: 43) CX₁₁CXCX₅C,  (SEQ ID NO: 44) CX₁₁CX₅CX₅CXCX₇C,(SEQ ID NO: 45) CX₁₀CX₆CX₅CXCX₁₃C,  (SEQ ID NO: 46) CX₁₀CX₅CXCX₄CX₈C,(SEQ ID NO: 47) CX₁₀CX₆CX₆CXCX₇C,  (SEQ ID NO: 48) CX₁₀CX₄CX₇CXCX₈C,(SEQ ID NO: 49) CX₁₀CX₄CX₇CXCX₇C,  (SEQ ID NO: 50) CX₁₃CX₈CX₈C,(SEQ ID NO: 51) CX₁₀CX₆CX₅CXCX₇C,  (SEQ ID NO: 52) CX₁₀CX₅CX₅C,(SEQ ID NO: 53) CX₁₀CX₅CX₆CXCX₇C, (SEQ ID NO: 54) CX₁₀CX₆CX₅CX₇CX₉C,(SEQ ID NO: 55) CX₉CX₇CX₅CXCX₇C,  (SEQ ID NO: 56) CX₁₀CX₆CX₅CXCX₉C,(SEQ ID NO: 57) CX₁₀CXCX₄CX₅CX₁₁C,  (SEQ ID NO: 58)CX₇CX₃CX₆CX₅CXCX₅CX₁₀C, (SEQ ID NO: 59) CX₁₀CXCX₄CX₅CXCX₂CX₃C, (SEQ ID NO: 60) CX₁₆CX₅CXC, (SEQ ID NO: 61) CX₆CX₄CXCX₄CX₅C, (SEQ ID NO: 62) CX₁₁CX₄CX₅CX₆CX₃C, (SEQ ID NO: 63) CX₈CX₂CX₆CX₅C, (SEQ ID NO: 64) CX₁₀CX₅CX₅CXCX₁₀C, (SEQ ID NO: 65) CX₁₀CXCX₆CX₄CXC, (SEQ ID NO: 66) CX₁₀CX₅CX₅CXCX₂C, (SEQ ID NO: 67) CX₁₄CX₂CX₃CXCXC, (SEQ ID NO: 68) CX₁₅CX₅CXC, (SEQ ID NO: 69) CX₄CX₆CX₉CX₂CX₁₁C, (SEQ ID NO: 70) CX₆CX₄CX₅CX₅CX₁₂C, (SEQ ID NO: 71)CX₇CX₃CXCXCX₄CX₅CX₉C,  (SEQ ID NO: 72) CX₁₀CX₆CX₅C, (SEQ ID NO: 73)CX₇CX₃CX₅CX₅CX₉C,  (SEQ ID NO: 74) CX₇CX₅CXCX₂C,  (SEQ ID NO: 75)CX₁₀CXCX₆C,  (SEQ ID NO: 76) CX₁₀CX₃CX₃CX₅CX₇CXCX₆C,  (SEQ ID NO: 77)CX₁₀CX₄CX₅CX₁₂CX₂C,  (SEQ ID NO: 78) CX₁₂CX₄CX₅CXCXCX₉CX₃C, (SEQ ID NO: 79) CX₁₂CX₄CX₅CX₁₂CX₂C, (SEQ ID NO: 80) CX₁₀CX₆CX₅CXCX₁₁C, (SEQ ID NO: 81) CX₁₆CX₅CXCXCX₁₄C,  (SEQ ID NO: 82) CX₁₀CX₅CXCX₈CX₆C, (SEQ ID NO: 83) CX₁₂CX₄CX₅CX₈CX₂C, (SEQ ID NO: 84) CX₁₂CX₅CX₅CXCX₈C, (SEQ ID NO: 85) CX₁₀CX₆CX₅CXCX₄CXCX₉C, (SEQ ID NO: 86)CX₁₁CX₄CX₅CX₈CX₂C,  (SEQ ID NO: 87) CX₁₀CX₆CX₅CX₈CX₂C, (SEQ ID NO: 88)CX₁₀CX₆CX₅CXCX₈C,  (SEQ ID NO: 89) CX₁₀CX₆CX₅CXCX₃CX₈CX₂C,(SEQ ID NO: 90) CX₁₀CX₆CX₅CX₃CX₈C,  (SEQ ID NO: 91)CX₁₀CX₆CX₅CXCX₂CX₆CX₅C, (SEQ ID NO: 92) CX₇CX₆CX₃CX₃CX₉C, (SEQ ID NO: 93) CX₉CX₈CX₅CX₆CX₅C, (SEQ ID NO: 94)CX₁₀CX₂CX₂CX₇CXCX₁₁CX₅C,  and  (SEQ ID NO: 95) CX₁₀CX₆CX₅CXCX₂CX₈CX₄C.Alternatively, the ultralong CDR3 may comprise a cysteine motifincluding, for example, where the cysteine motif is selected from thegroup consisting of:

(SEQ ID NO: 96) CCX₃CXCX₃CX₂CCXCX₅CX₉CX₅CXC,  (SEQ ID NO: 97)CX₆CX₂CX₅CX₄CCXCX₄CX₆CXC,  (SEQ ID NO: 98) CX₇CXCX₅CX₄CCCX₄CX₆CXC,(SEQ ID NO: 99) CX₉CX₃CXCX₂CXCCCX₆CX₄C,  (SEQ ID NO: 100)CX₅CX₃CXCX₄CX₄CCX₁₀CX₂CC,  (SEQ ID NO: 101) CX₅CXCX₁CXCX₃CCX₃CX₄CX₁₀C,(SEQ ID NO: 102) CX₉CCCX₃CX₄CCCX₅CX₆C,  (SEQ ID NO: 103)CCX₈CX₅CX₄CX₃CX₄CCXCX₁C,  (SEQ ID NO: 104) CCX₆CCX₅CCCX₄CX₄CX₁₂C,(SEQ ID NO: 105) CX₆CX₂CX₃CCCX₄CX₅CX₃CX₃C,  (SEQ ID NO: 106)CX₃CX₅CX₆CX₄CCXCX₅CX₄CXC, (SEQ ID NO: 107) CX₄CX₄CCX₄CX₄CXCX₁₁CX₂CXC,(SEQ ID NO: 108) CX₅CX₂CCX₅CX₄CCX₃CCX₇C,  (SEQ ID NO: 109)CX₅CX₅CX₃CX₂CXCCX₄CX₇CXC, (SEQ ID NO: 110) CX₃CX₇CX₃CX₄CCXCX₂CX₅CX₂C,(SEQ ID NO: 111) CX₉CX₃CXCX₄CCX₅CCCX₆C,  (SEQ ID NO: 112)CX₉CX₃CXCX₂CXCCX₆CX₃CX₃C, (SEQ ID NO: 113) CX₈CCXCX₃CCX₃CXCX₃CX₄C,(SEQ ID NO: 114) CX₉CCX₄CX₂CXCCXCX₄CX₃C,  (SEQ ID NO: 115)CX₁₀CXCX₃CX₂CXCCX₄CX₅CXC, (SEQ ID NO: 116) CX₉CXCX₃CX₂CXCCX₄CX₅CXC,(SEQ ID NO: 117) CX₆CCXCX₅CX₄CCXCX₅CX₂C,  (SEQ ID NO: 118)CX₆CCXCX₃CXCCX₃CX₄CC, (SEQ ID NO: 119) CX₆CCXCX₃CXCX₂CXCX₄CX₈C,(SEQ ID NO: 120) CX₄CX₂CCX₃CXCX₄CCX₂CX₃C,  (SEQ ID NO: 121)CX₃CX₅CX₃CCCX₄CX₉C,  (SEQ ID NO: 122) CCX₉CX₃CXCCX₃CX₅C, (SEQ ID NO: 123) CX₉CX₂CX₃CX₄CCX₄CX₅C,  (SEQ ID NO: 124)CX₉CX₇CX₄CCXCX₇CX₃C,  (SEQ ID NO: 125) CX₉CX₃CCCX₁₀CX₂CX₃C, (SEQ ID NO: 126) CX₃CX₅CX₅CX₄CCX₁₀CX₆C,  (SEQ ID NO: 127)CX₉CX₅CX₄CCXCX₅CX₄C,  (SEQ ID NO: 128) CX₇CXCX₆CX₄CCCX₁₀C, (SEQ ID NO: 129) CX₈CX₂CX₄CCX₄CX₃CX₃C,  (SEQ ID NO: 130)CX₇CX₅CXCX₄CCX₇CX₄C,  (SEQ ID NO: 131) CX₁₁CX₃CX₄CCCX₈CX₂C, (SEQ ID NO: 132) CX₂CX₃CX₄CCX₄CX₅CX₁₅C,  (SEQ ID NO: 133)CX₉CX₅CX₄CCX₇C,  (SEQ ID NO: 134) CX₉CX₇CX₃CX₂CX₆C,  (SEQ ID NO: 135)CX₉CX₅CX₄CCX₁₄C, (SEQ ID NO: 136) CX₉CX₅CX₄CCX₈C,  (SEQ ID NO: 137)CX₉CX₆CX₄CCXC, (SEQ ID NO: 138) CX₅CCX₇CX₄CX₁₂,  (SEQ ID NO: 139)CX₁₀CX₃CX₄CCX₄C, (SEQ ID NO: 140) CX₉CX₄CCX₅CX₄C,  (SEQ ID NO: 141)CX₁₀CX₃CX₄CX₇CXC, (SEQ ID NO: 142) CX₇CX₇CX₂CX₂CX₃C,  (SEQ ID NO: 143)CX₉CX₄CX₄CCX₆C, (SEQ ID NO: 144) CX₇CXCX₃CXCX₆C,  (SEQ ID NO: 145)CX₇CXCX₄CXCX₄C, (SEQ ID NO: 146) CX₉CX₅CX₄C,  (SEQ ID NO: 147)CX₃CX₆CX₈C,  (SEQ ID NO: 148) CX₁₀CXCX₄C,  (SEQ ID NO: 149) CX₁₀CCX₄C, (SEQ ID NO: 150) CX₁₅C,  (SEQ ID NO: 151) CX₁₀C,  and  (SEQ ID NO: 152)CX₉C.

The present disclosure provides a humanized antibody or binding fragmentthereof comprising an ultralong CDR3, wherein the ultralong CDR3comprises a X¹X²X³X⁴X⁵ motif, wherein X¹ is threonine (T), glycine (G),alanine (A), serine (S), or valine (V), wherein X² is serine (S),threonine (T), proline (P), isoleucine (I), alanine (A), valine (V), orasparagine (N), wherein X³ is valine (V), alanine (A), threonine (T), oraspartic acid (D), wherein X⁴ is histidine (H), threonine (T), arginine(R), tyrosine (Y), phenylalanine (F), or leucine (L), and wherein X⁵ isglutamine (Q). In some embodiments, the X¹X²X³X⁴X⁵ motif may be TTVHQ(SEQ ID NO: 153), TSVHQ (SEQ ID NO: 154), SSVTQ (SEQ ID NO: 155), STVHQ(SEQ ID NO: 156), ATVRQ (SEQ ID NO: 157), TTVYQ (SEQ ID NO: 158), SPVHQ(SEQ ID NO: 159), ATVYQ (SEQ ID NO: 160), TAVYQ (SEQ ID NO: 161), TNVHQ(SEQ ID NO: 162), ATVHQ (SEQ ID NO: 163), STVYQ (SEQ ID NO: 164), TIVHQ(SEQ ID NO: 165), AIVYQ (SEQ ID NO: 166), TTVFQ (SEQ ID NO: 167), AAVFQ(SEQ ID NO: 168), GTVHQ (SEQ ID NO: 169), ASVHQ (SEQ ID NO: 170), TAVFQ(SEQ ID NO: 171), ATVFQ (SEQ ID NO: 172), AAAHQ (SEQ ID NO: 173), VVVYQ(SEQ ID NO: 174), GTVFQ (SEQ ID NO: 175), TAVHQ (SEQ ID NO: 176), ITVHQ(SEQ ID NO: 177), ITAHQ (SEQ ID NO: 178), VTVHQ (SEQ ID NO: 179); AAVHQ(SEQ ID NO: 180), GTVYQ (SEQ ID NO: 181), TTVLQ (SEQ ID NO: 182), TTTHQ(SEQ ID NO: 183), or TTDYQ (SEQ ID NO: 184).

The present disclosure provides a humanized antibody or binding fragmentthereof comprising an ultralong CDR3, wherein the ultralong CDR3comprises a (X^(a)X^(b))_(z) motif, wherein X^(a) is any amino acidresidue, X^(b) is an aromatic amino acid selected from the groupconsisting of: tyrosine (Y), phenylalanine (F), tryptophan (W), andhistidine (H), and wherein z is 1-4. In some embodiments, the(X^(a)X^(b))_(z) motif may be CYTYNYEF (SEQ ID NO: 217), HYTYTYDF (SEQID NO: 218), HYTYTYEW (SEQ ID NO: 219), KHRYTYEW (SEQ ID NO: 220),NYIYKYSF (SEQ ID NO: 221), PYIYTYQF (SEQ ID NO: 222), SFTYTYEW (SEQ IDNO: 223), SYIYIYQW (SEQ ID NO: 224), SYNYTYSW (SEQ ID NO: 225), SYSYSYEY(SEQ ID NO: 226), SYTYNYDF (SEQ ID NO: 227), SYTYNYEW (SEQ ID NO: 228),SYTYNYQF (SEQ ID NO: 229), SYVWTHNF (SEQ ID NO: 230), TYKYVYEW (SEQ IDNO: 231), TYTYTYEF (SEQ ID NO: 232), TYTYTYEW (SEQ ID NO: 233), VFTYTYEF(SEQ ID NO: 234), AYTYEW (SEQ ID NO: 235), DYIYTY (SEQ ID NO: 236),IHSYEF (SEQ ID NO: 237), SFTYEF (SEQ ID NO: 238), SHSYEF (SEQ ID NO:239), THTYEF (SEQ ID NO: 240), TWTYEF (SEQ ID NO: 241), TYNYEW (SEQ IDNO: 242), TYSYEF (SEQ ID NO: 243), TYSYEH (SEQ ID NO: 244), TYTYDF (SEQID NO: 245), TYTYEF (SEQ ID NO: 246), TYTYEW (SEQ ID NO: 247), AYEF (SEQID NO: 248), AYSF (SEQ ID NO: 249), AYSY (SEQ ID NO: 250), CYSF (SEQ IDNO: 251), DYTY (SEQ ID NO: 252), KYEH (SEQ ID NO: 253), KYEW (SEQ ID NO:254), MYEF (SEQ ID NO: 255), NWIY (SEQ ID NO: 256), NYDY (SEQ ID NO:257), NYQW (SEQ ID NO: 258), NYSF (SEQ ID NO: 259), PYEW (SEQ ID NO:260), RYNW (SEQ ID NO: 261), RYTY (SEQ ID NO: 262), SYEF (SEQ ID NO:263), SYEH (SEQ ID NO: 264), SYEW (SEQ ID NO: 265), SYKW (SEQ ID NO:266), SYTY (SEQ ID NO: 267), TYDF (SEQ ID NO: 268), TYEF (SEQ ID NO:269), TYEW (SEQ ID NO: 270), TYQW (SEQ ID NO: 271), TYTY (SEQ ID NO:272), or VYEW (SEQ ID NO: 273).

The present disclosure provides a humanized antibody or binding fragmentthereof comprising an ultralong CDR3, wherein the ultralong CDR3comprises a X¹X²X³X⁴X⁵X_(n)(X^(a)X^(b))_(z) motif, wherein X¹ isthreonine (T), glycine (G), alanine (A), serine (S), or valine (V),wherein X² is serine (S), threonine (T), proline (P), isoleucine (I),alanine (A), valine (V), or asparagine (N), wherein X³ is valine (V),alanine (A), threonine (T), or aspartic acid (D), wherein X⁴ ishistidine (H), threonine (T), arginine (R), tyrosine (Y), phenylalanine(F), or leucine (L), and wherein X⁵ is glutamine (Q), wherein X^(a) isany amino acid residue, X^(b) is an aromatic amino acid selected fromthe group consisting of: tyrosine (Y), phenylalanine (F), tryptophan(W), and histidine (H), wherein n is 27-54, and wherein z is 1-4.

The present disclosure provides a humanized antibody or binding fragmentthereof comprising an ultralong CDR3, wherein the ultralong CDR3comprises: a CX¹X²X³X⁴X⁵ motif, wherein X¹ is threonine (T), glycine(G), alanine (A), serine (S), or valine (V), wherein X² is serine (S),threonine (T), proline (P), isoleucine (I), alanine (A), valine (V), orasparagine (N), wherein X³ is valine (V), alanine (A), threonine (T), oraspartic acid (D), wherein X⁴ is histidine (H), threonine (T), arginine(R), tyrosine (Y), phenylalanine (F), or leucine (L), and wherein X⁵ isglutamine (Q), a cysteine motif selected from the group consisting of:CX₁₀CX₅CX₅CXCX₇C (SEQ ID NO: 41), CX₁₀CX₆CX₅CXCX₁₅C (SEQ ID NO: 42),CX₁₁CXCX₅C (SEQ ID NO: 43), CX₁₁CX₅CX₅CXCX₇C (SEQ ID NO: 44),CX₁₀CX₆CX₅CXCX₁₃C (SEQ ID NO: 45), CX₁₀CX₅CXCX₄CX₈C (SEQ ID NO: 46),CX₁₀CX₆CX₆CXCX₇C (SEQ ID NO: 47), CX₁₀CX₄CX₇CXCX₈C (SEQ ID NO: 48),CX₁₀CX₄CX₇CXCX₇C (SEQ ID NO: 49), CX₁₃CX₈CX₈C (SEQ ID NO: 50),CX₁₀CX₆CX₅CXCX₇C (SEQ ID NO: 51), CX₁₀CX₅CX₅C (SEQ ID NO: 52),CX₁₀CX₅CX₆CXCX₇C (SEQ ID NO: 53), CX₁₀CX₆CX₅CX₇CX₈C (SEQ ID NO: 54),CX₉CX₇CX₅CXCX₇C (SEQ ID NO: 55), CX₁₀CX₆CX₅CXCX₈C (SEQ ID NO: 56),CX₁₀CXCX₄CX₅CX₁₁C (SEQ ID NO: 57), CX₇CX₃CX₆CX₅CXCX₅CX₁₀C (SEQ ID NO:58), CX₁₀CXCX₄CX₅CXCX₂CX₃C (SEQ ID NO: 59), CX₁₆CX₅CXC (SEQ ID NO: 60),CX₆CX₄CXCX₄CX₅C (SEQ ID NO: 61), CX₁₁CX₄CX₅CX₆CX₃C (SEQ ID NO: 62),CX₈CX₂CX₆CX₅C (SEQ ID NO: 63), CX₁₀CX₅CX₅CXCX₁₀C (SEQ ID NO: 64),CX₁₀CXCX₆CX₄CXC (SEQ ID NO: 65), CX₁₀CX₅CX₅CXCX₂C (SEQ ID NO: 66),CX₁₄CX₂CX₃CXCXC (SEQ ID NO: 67), CX₁₅CX₅CXC (SEQ ID NO: 68),CX₄CX₆CX₉CX₂CX₁₁C (SEQ ID NO: 69), CX₆CX₄CX₅CX₅CX₁₂C (SEQ ID NO: 70),CX₇CX₃CXCXCX₄CX₅CX₉C (SEQ ID NO: 71), CX₁₀CX₆CX₅C (SEQ ID NO: 72),CX₇CX₃CX₅CX₅CX₉C (SEQ ID NO: 73), CX₇CX₅CXCX₂C (SEQ ID NO: 74),CX₁₀CXCX₆C (SEQ ID NO: 75), CX₁₀CX₃CX₃CX₅CX₇CXCX₆C (SEQ ID NO: 76),CX₁₀CX₄CX₅CX₁₂CX₂C (SEQ ID NO: 77), CX₁₂CX₄CX₅CXCXCX₉CX₃C (SEQ ID NO:78), CX₁₂CX₄CX₅CX₁₂CX₂C (SEQ ID NO: 79), CX₁₀CX₆CX₅CXCX₁₁C (SEQ ID NO:80), CX₁₆CX₅CXCXCX₁₄C (SEQ ID NO: 81), CX₁₀CX₅CXCX₈CX₆C (SEQ ID NO: 82),CX₁₂CX₄CX₅CX₈CX₂C (SEQ ID NO: 83), CX₁₂CX₅CX₅CXCX₈C (SEQ ID NO: 84),CX₁₀CX₆CX₅CXCX₄CXCX₉C (SEQ ID NO: 85), CX₁₁CX₄CX₅CX₈CX₂C (SEQ ID NO:86), CX₁₀CX₆CX₅CX₈CX₂C (SEQ ID NO: 87), CX₁₀CX₆CX₅CXCX₈C (SEQ ID NO:88), CX₁₀CX₆CX₅CXCX₃CX₈CX₂C (SEQ ID NO: 89), CX₁₀CX₆CX₅CX₃CX₈C (SEQ IDNO: 90), CX₁₀CX₆CX₅CXCX₂CX₆CX₅C (SEQ ID NO: 91), CX₇CX₆CX₃CX₃CX₉C (SEQID NO: 92), CX₉CX₈CX₅CX₆CX₅C (SEQ ID NO: 93), CX₁₀CX₂CX₂CX₇CXCX₁₁CX₅C(SEQ ID NO: 94), and CX₁₀CX₆CX₅CXCX₂CX₈CX₄C (SEQ ID NO: 95), and a(X^(a)X^(b)), motif, wherein X^(a) is any amino acid residue, X^(b) isan aromatic amino acid selected from the group consisting of: tyrosine(Y), phenylalanine (F), tryptophan (W), and histidine (H), and wherein zis 1-4.

The present disclosure provides a humanized antibody or binding fragmentthereof comprising an ultralong CDR3, wherein the ultralong CDR3comprises: a CX¹X²X³X⁴X⁵ motif, wherein X¹ is threonine (T), glycine(G), alanine (A), serine (S), or valine (V), wherein X² is serine (S),threonine (T), proline (P), isoleucine (I), alanine (A), valine (V), orasparagine (N), wherein X³ is valine (V), alanine (A), threonine (T), oraspartic acid (D), wherein X⁴ is histidine (H), threonine (T), arginine(R), tyrosine (Y), phenylalanine (F), or leucine (L), and wherein X⁵ isglutamine (Q); a cysteine motif selected from the group consisting of:wherein the cysteine motif is selected from the group consisting of:CCX₃CXCX₃CX₂CCXCX₅CX₉CX₅CXC (SEQ ID NO: 96), CX₆CX₂CX₅CX₄CCXCX₄CX₆CXC(SEQ ID NO: 97), CX₇CXCX₅CX₄CCCX₄CX₆CXC (SEQ ID NO: 98),CX₉CX₃CXCX₂CXCCCX₆CX₄C (SEQ ID NO: 99), CX₅CX₃CXCX₄CX₄CCX₁₀CX₂CC (SEQ IDNO: 100), CX₅CXCX₁CXCX₃CCX₃CX₄CX₁₀C (SEQ ID NO: 101),CX₉CCCX₃CX₄CCCX₅CX₆C (SEQ ID NO: 102), CCX₈CX₅CX₄CX₃CX₄CCXCX₁C (SEQ IDNO: 103), CCX₆CCX₅CCCX₄CX₄CX₁₂C (SEQ ID NO: 104),CX₆CX₂CX₃CCCX₄CX₅CX₃CX₃C (SEQ ID NO: 105), CX₃CX₅CX₆CX₄CCXCX₅CX₄CXC (SEQID NO: 106), CX₄CX₄CCX₄CX₄CXCX₁₁CX₂CXC (SEQ ID NO: 107),CX₅CX₂CCX₅CX₄CCX₃CCX₇C (SEQ ID NO: 108), CX₅CX₅CX₃CX₂CXCCX₄CX₇CXC (SEQID NO: 109), CX₃CX₇CX₃CX₄CCXCX₂CX₅CX₂C (SEQ ID NO: 110),CX₉CX₃CXCX₄CCX₅CCCX₆C (SEQ ID NO: 111), CX₉CX₃CXCX₂CXCCX₆CX₃CX₃C (SEQ IDNO: 112), CX₈CCXCX₃CCX₃CXCX₃CX₄C (SEQ ID NO: 113),CX₉CCX₄CX₂CXCCXCX₄CX₃C (SEQ ID NO: 114), CX₁₀CXCX₃CX₂CXCCX₄CX₅CXC (SEQID NO: 115), CX₉CXCX₃CX₂CXCCX₄CX₅CXC (SEQ ID NO: 116),CX₆CCXCX₅CX₄CCXCX₅CX₂C (SEQ ID NO: 117), CX₆CCXCX₃CXCCX₃CX₄CC (SEQ IDNO: 118), CX₆CCXCX₃CXCX₂CXCX₄CX₈C (SEQ ID NO: 119),CX₄CX₂CCX₃CXCX₄CCX₂CX₃C (SEQ ID NO: 120), CX₃CX₅CX₃CCCX₄CX₉C (SEQ ID NO:121), CCX₉CX₃CXCCX₃CX₅C (SEQ ID NO: 122), CX₉CX₂CX₃CX₄CCX₄CX₅C (SEQ IDNO: 123), CX₉CX₇CX₄CCXCX₇CX₃C (SEQ ID NO: 124), CX₉CX₃CCCX₁₀CX₂CX₃C (SEQID NO: 125), CX₃CX₅CX₅CX₄CCX₁₀CX₆C (SEQ ID NO: 126), CX₉CX₅CX₄CCXCX₅CX₄C(SEQ ID NO: 127), CX₇CXCX₆CX₄CCCX₁₀C (SEQ ID NO: 128),CX₈CX₂CX₄CCX₄CX₃CX₃C (SEQ ID NO: 129), CX₇CX₅CXCX₄CCX₇CX₄C (SEQ ID NO:130), CX₁₁CX₃CX₄CCCX₈CX₂C (SEQ ID NO: 131), CX₂CX₃CX₄CCX₄CX₅CX₁₅C (SEQID NO: 132), CX₉CX₅CX₄CCX₇C (SEQ ID NO: 133), CX₉CX₇CX₃CX₂CX₆C (SEQ IDNO: 134), CX₉CX₅CX₄CCX₁₄C (SEQ ID NO: 135), CX₉CX₅CX₄CCX₈C (SEQ ID NO:136), CX₉CX₆CX₄CCXC (SEQ ID NO: 137), CX₅CCX₇CX₄CX₁₂ (SEQ ID NO: 138),CX₁₀CX₃CX₄CCX₄C (SEQ ID NO: 139), CX₉CX₄CCX₅CX₄C (SEQ ID NO: 140),CX₁₀CX₃CX₄CX₇CXC (SEQ ID NO: 141), CX₇CX₇CX₂CX₂CX₃C (SEQ ID NO: 142),CX₉CX₄CX₄CCX₆C (SEQ ID NO: 143), CX₇CXCX₃CXCX₆C (SEQ ID NO: 144),CX₇CXCX₄CXCX₄C (SEQ ID NO: 145), CX₉CX₅CX₄C (SEQ ID NO: 146), CX₃CX₆CX₈C(SEQ ID NO: 147), CX₁₀CXCX₄C (SEQ ID NO: 148), CX₁₀CCX₄C (SEQ ID NO:149), CX₁₅C (SEQ ID NO: 150), CX₁₀C (SEQ ID NO: 151), and CX₉C (SEQ IDNO: 152); and a (X^(a)X^(b))_(z) motif, wherein X^(a) is any amino acidresidue, X^(b) is an aromatic amino acid selected from the groupconsisting of: tyrosine (Y), phenylalanine (F), tryptophan (W), andhistidine (H), and wherein z is 1-4.

The present disclosure also provides methods of generating a library ofhumanized antibodies that comprises an ultralong CDR3, comprising:combining a nucleic acid sequence encoding an ultralong CDR3 with anucleic acid sequence encoding a human variable region framework (FR)sequence to produce nucleic acids encoding for humanized antibodies thatcomprises an ultralong CDR3; and expressing the nucleic acids encodingfor humanized antibodies that comprises an ultralong CDR3 to generate alibrary of humanized antibodies that comprises an ultralong CDR3.

The present disclosure also provides methods of generating a library ofhumanized antibodies or binding fragments thereof comprising anultralong CDR3 that comprises a non-antibody sequence, comprising:combining a nucleic acid sequence encoding an ultralong CDR3, a nucleicacid sequence encoding a human variable region framework (FR) sequence,and a nucleic acid sequence encoding a non-antibody sequence to producenucleic acids encoding humanized antibodies or binding fragments thereofcomprising an ultralong CDR3 and a non-antibody sequence, and expressingthe nucleic acids encoding humanized antibodies or binding fragmentsthereof comprising an ultralong CDR3 and a non-antibody sequence togenerate a library of humanized antibodies or binding fragments thereofcomprising an ultralong CDR3 and a non-antibody sequence.

The present disclosure also provides libraries of humanized antibodiesor binding fragments thereof comprising an ultralong CDR3 that comprisesa non-antibody sequence.

The present disclosure also provides methods of generating a library ofhumanized antibodies or binding fragments thereof comprising anultralong CDR3 that comprises a cysteine motif, comprising: combining ahuman variable region framework (FR) sequence, and a nucleic acidsequence encoding an ultralong CDR3 and a cysteine motif; introducingone or more nucleotide changes to the nucleic acid sequence encoding oneor more amino acid residues that are positioned between one or morecysteine residues in the cysteine motif for nucleotides encodingdifferent amino acid residues to produce nucleic acids encodinghumanized antibodies or binding fragments thereof comprising anultralong CDR3 and a cysteine motif with one or more nucleotide changesintroduced between one or more cysteine residues in the cysteine domain;and expressing the nucleic acids encoding humanized antibodies orbinding fragments thereof comprising an ultralong CDR3 and a cysteinemotif with one or more nucleotide changes introduced between one or morecysteine residues in the cysteine domain to generate a library ofhumanized antibodies or binding fragments thereof comprising anultralong CDR3 and a cysteine motif with one or more amino acid changesintroduced between one or more cysteine residues in the cysteine domain.

The present disclosure also provides libraries of humanized antibodiesor binding fragments thereof comprising an ultralong CDR3 that comprisesa cysteine motif, wherein the antibodies or binding fragments compriseone or more substitutions of amino acid residues that are positionedbetween cysteine residues in the cysteine motif.

The present disclosure also provides methods of generating a library ofhumanized antibodies or binding fragments thereof comprising a bovineultralong CDR3, comprising: combining a nucleic acid sequence encoding ahuman variable region framework (FR) sequence and a nucleic acidencoding a bovine ultralong CDR3, and expressing the nucleic acidsencoding a human variable region framework (FR) sequence and a nucleicacid encoding a bovine ultralong CDR3 to generate a library of humanizedantibodies or binding fragments thereof comprising a bovine ultralongCDR3.

The present disclosure also provides a CDR3 scaffold comprising aX¹X²X³X⁴X⁵ motif, wherein X¹ is threonine (T), glycine (G), alanine (A),serine (S), or valine (V), wherein X² is serine (S), threonine (T),proline (P), isoleucine (I), alanine (A), valine (V), or asparagine (N),wherein X³ is valine (V), alanine (A), threonine (T), or aspartic acid(D), wherein X⁴ is histidine (H), threonine (T), arginine (R), tyrosine(Y), phenylalanine (F), or leucine (L), and wherein X⁵ is glutamine (Q).

Proteins

The present disclosure provides humanized antibodies comprisingultralong CDR3 sequences.

In an embodiment, the present disclosure provides a humanized antibodycomprising an ultralong CDR3, wherein the CDR3 is 35 amino acids inlength or more (e.g., 40 or more, 45 or more, 50 or more, 55 or more, 60or more). Such a humanized antibody may comprise at least 3 cysteineresidues or more (e.g., 4 or more, 6 or more, 8 or more) within theultralong CDR3.

In another embodiment, the present disclosure provides a humanizedantibody comprising an ultralong CDR3, wherein the CDR3 is 35 aminoacids in length or more and is derived from or based on a non-humansequence. The ultralong CDR3 sequence may be derived from any speciesthat naturally produces ultralong CDR3 antibodies, including ruminantssuch as cattle (Bos taurus).

In another embodiment, the present disclosure provides a humanizedantibody comprising an ultralong CDR3, wherein the CDR3 is 35 aminoacids in length or more and is derived from a non-antibody sequence. Thenon-antibody sequence may be derived from any protein family including,but not limited to, chemokines, growth factors, peptides, cytokines,cell surface proteins, serum proteins, toxins, extracellular matrixproteins, clotting factors, secreted proteins, etc. The non-antibodysequence may be of human or non-human origin and may comprise a portionof a non-antibody protein such as a peptide or domain. The non-antibodysequence of an ultralong CDR3 may contain mutations from its naturalsequence, including amino acid changes (e.g., substitutions), insertionsor deletions. Engineering additional amino acids at the junction betweenthe non-antibody sequence may be done to facilitate or enhance properfolding of the non-antibody sequence within the humanized antibody.

In another embodiment, the present disclosure provides a humanizedantibody comprising an ultralong CDR3, wherein the CDR3 is 35 aminoacids in length or more and comprises at least 3 cysteine residues ormore, including, for example, 4 or more, 6 or more, and 8 or more.

In another embodiment, the present disclosure provides for a humanizedantibody comprising an ultralong CDR3 wherein the CDR3 is 35 amino acidsin length or more and comprises at least 3 cysteine residues or more andwherein the ultralong CDR3 is a component of a multispecific antibody.The multispecific antibody may be bispecific or comprise greatervalencies.

In another embodiment, the present disclosure provides a humanizedantibody comprising an ultralong CDR3, wherein the CDR3 is 35 aminoacids in length or more and comprises at least 3 cysteine residues ormore, wherein the partially human ultralong CDR3 is a component of animmunoconjugate.

In another embodiment, the present disclosure provides a humanizedantibody comprising an ultralong CDR3, wherein the CDR3 is 35 aminoacids in length or more and comprises at least 3 cysteine residues ormore, wherein the humanized antibody comprising an ultralong CDR3 bindsto a transmembrane protein target. Such transmembrane targets mayinclude, but are not limited to, GPCRs, ion channels, transporters, andcell surface receptors.

Genetic Sequences

The present disclosure provides genetic sequences (e.g., genes, nucleicacids, polynucleotides) encoding humanized antibodies comprisingultralong CDR sequences.

The present disclosure also provides genetic sequences (e.g., genes,nucleic acids, polynucleotides) encoding an ultralong CDR3.

In an embodiment, the present disclosure provides genetic sequencesencoding a humanized antibody comprising an ultralong CDR3, wherein theCDR3 is 35 amino acids in length or more (e.g., 40 or more, 45 or more,50 or more, 55 or more, 60 or more). Such a humanized antibody maycomprise at least 3 cysteine residues or more (e.g., 4 or more, 6 ormore, 8 or more) within the ultralong CDR3.

In another embodiment, the present disclosure provides genetic sequencesencoding a humanized antibody comprising an ultralong CDR3, wherein theCDR3 is 35 amino acids in length or more and is derived from or based ona non-human sequence. The genetic sequences encoding the ultralong CDR3may be derived from any species that naturally produces ultralong CDR3antibodies, including ruminants such as cattle (Bos taurus).

In another embodiment, the present disclosure provides genetic sequencesencoding a humanized antibody comprising an ultralong CDR3, wherein theCDR3 is 35 amino acids in length or more and is derived from anon-antibody protein sequence. The genetic sequences encoding thenon-antibody protein sequences may be derived from any protein familyincluding, but not limited to, chemokines, growth factors, peptides,cytokines, cell surface proteins, serum proteins, toxins, extracellularmatrix proteins, clotting factors, secreted proteins, etc. Thenon-antibody protein sequence may be of human or non-human origin andmay comprise a portion of a non-antibody protein such as a peptide ordomain. The non-antibody protein sequence of an ultralong CDR3 maycontain mutations from its natural sequence, including amino acidchanges (e.g., substitutions), insertions or deletions. Engineeringadditional amino acids at the junction between the non-antibody sequencemay be done to facilitate or enhance proper folding of the non-antibodysequence within the humanized antibody.

In another embodiment, the present disclosure provides genetic sequencesencoding a humanized antibody comprising an ultralong CDR3, wherein theCDR3 is 35 amino acids in length or more and comprises at least 3cysteine residues or more, including, for example, 4 or more, 6 or more,and 8 or more.

In another embodiment, the present disclosure provides genetic sequencesencoding a humanized antibody comprising an ultralong CDR3 wherein theCDR3 is 35 amino acids in length or more and comprises at least 3cysteine residues or more and wherein the ultralong CDR3 is a componentof a multispecific antibody. The multispecific antibody may bebispecific or comprise greater valencies.

In another embodiment, the present disclosure provides genetic sequencesencoding a humanized antibody comprising an ultralong CDR3, wherein theCDR3 is 35 amino acids in length or more and comprises at least 3cysteine residues or more, wherein the ultralong CDR3 is a component ofan immunoconjugate.

In another embodiment, the present disclosure provides genetic sequencesencoding a humanized antibody comprising an ultralong CDR3 wherein theCDR3 is 35 amino acids in length or more and comprises at least 3cysteine residues or more and wherein the humanized antibody comprisingan ultralong CDR3 binds to a transmembrane protein target. Suchtransmembrane targets may include, but are not limited to, GPCRs, ionchannels, transporters, and cell surface receptors.

Libraries and Arrays

The present disclosure provides collections, libraries, and arrays ofhumanized antibodies comprising ultralong CDR3 sequences.

In an embodiment, the present disclosure provides a library or an arrayof humanized antibodies comprising ultralong CDR3 sequences wherein atleast two members of the library or array differ in the positions of atleast one of the cysteines in the ultralong CDR3 sequence. Structuraldiversity may be enhanced through different numbers of cysteines in theultralong CDR3 sequence (e.g., at least 3 or more cysteine residues suchas 4 or more, 6 or more and 8 or more) and/or through differentdisulfide bond formation, and hence different loop structures.

In another embodiment, the present disclosure provides for a library oran array of humanized antibodies comprising ultralong CDR3 sequenceswherein at least two members of the library or the array differ in atleast one amino acid located between cysteines in the ultralong CDR3. Inthis regard, members of the library or the array can contain cysteinesin the same positions of CDR3, resulting in similar overall structuralfolds, but with fine differences brought about through different aminoacid side chains. Such libraries or arrays may be useful for affinitymaturation.

In another embodiment, the present disclosure provides libraries orarrays of humanized antibodies comprising ultralong CDR3 sequenceswherein at least two of the ultralong CDR3 sequences differ in length(e.g., 35 amino acids in length or more such as 40 or more, 45 or more,50 or more, 55 or more and 60 or more). The amino acid and cysteinecontent may or may not be altered between the members of the library orthe array. Different lengths of ultralong CDR3 sequences may provide forunique binding sites, including, for example, due to steric differences,as a result of altered length.

In another embodiment, the present disclosure provides libraries orarrays of humanized antibodies comprising ultralong CDR3 sequenceswherein at least two members of the library differ in the humanframework used to construct the humanized antibody comprising anultralong CDR3.

In another embodiment, the present disclosure provides libraries orarrays of humanized antibodies comprising ultralong CDR3 sequenceswherein at least two members of the library or the array differ inhaving a non-antibody protein sequence that comprises a portion of theultralong CDR3. Such libraries or arrays may contain multiplenon-antibody protein sequences, including for chemokines, growthfactors, peptides, cytokines, cell surface proteins, serum proteins,toxins, extracellular matrix proteins, clotting factors, secretedproteins, viral or bacterial proteins, etc. The non-antibody proteinsequence may be of human or non-human origin and may be comprised of aportion of a non-antibody protein such as a peptide or domain. Thenon-antibody protein sequence of the ultralong CDR3 may containmutations from its natural sequence, including amino acid changes (e.g.,substitutions), or insertions or deletions. Engineering additional aminoacids at the junction between the non-antibody sequence within theultralong CDR3 may be done to facilitate or enhance proper folding ofthe non-antibody sequence within the humanized antibody.

The libraries or the arrays of the present disclosure may be in severalformats well known in the art. The library or the array may be anaddressable library or an addressable array. The library or array may bein display format, for example, the antibody sequences may be expressedon phage, ribosomes, mRNA, yeast, or mammalian cells.

Cells

The present disclosure provides cells comprising genetic sequencesencoding humanized antibodies comprising ultralong CDR3 sequences.

In an embodiment, the present disclosure provides cells expressing ahumanized antibody comprising an ultralong CDR3. The cells may beprokaryotic or eukaryotic, and a humanized antibody comprising anultralong CDR3 may be expressed on the cell surface or secreted into themedia. When displayed on the cell surface a humanized antibodypreferentially contains a motif for insertion into the plasmid membranesuch as a membrane spanning domain at the C-terminus or a lipidattachment site. For bacterial cells, a humanized antibody comprising anultralong CDR3 may be secreted into the periplasm. When the cells areeukaryotic, they may be transiently transfected with genetic sequencesencoding a humanized antibody comprising an ultralong CDR3.Alternatively, a stable cell line or stable pools may be created bytransfecting or transducing genetic sequences encoding a humanizedantibody comprising an ultralong CDR3 by methods well known to those ofskill in the art. Cells can be selected by fluorescence activated cellsorting (FACS) or through selection for a gene encoding drug resistance.Cells useful for producing humanized antibodies comprising ultralongCDR3 sequences include prokaryotic cells like E. coli, eukaryotic cellslike the yeasts Saccharomyces cerevisiae and Pichia pastoris, chinesehamster ovary (CHO) cells, monkey cells like COS-1, or human cells likeHEK-293, HeLa, SP-1.

Humanization Methods

The present disclosure provides methods for making humanized antibodiescomprising ultralong CDR3 sequences, comprising the steps of engineeringan ultralong CDR3 sequence derived from a non-human CDR3 into a humanframework. The human framework may be of germline origin, or may bederived from non-germline (e.g. mutated or affinity matured) sequences.Genetic engineering techniques well known to those in the art, includingas disclosed herein, may be used to generate a hybrid DNA sequencecontaining a human framework and a non-human ultralong CDR3. Unlikehuman antibodies which may be encoded by V region genes derived from oneof seven families, bovine antibodies which produce ultralong CDR3sequences appear to utilize a single V region family which may beconsidered to be most homologous to the human VH4 family. In a preferredembodiment where ultralong CDR3 sequences derived from cattle are to behumanized to produce an antibody comprising an ultralong CDR3, human Vregion sequences derived from the VH4 family may be genetically fused toa bovine-derived ultralong CDR3 sequence. Exemplary VH4 germline genesequences in the human antibody locus are shown in FIG. 5A (e.g., SEQ IDNOS: 31-34; and 368-371).

The present disclosure also provides methods of humanizing an antibodyvariable region comprising the step of genetically combining a nucleicacid sequence encoding a non-human ultralong CDR3 (ULCDR3) with anucleic acid sequence encoding a human variable region framework (FR)sequence. Also provided are methods of making a humanized antibodyvariable region comprising selecting a human framework sequencecomprising FR1, FR2, and FR3; selecting a CDR1 sequence; selecting aCDR2 sequence; selecting an ultralong CDR3 sequence; and combining thesequences as FR1-CDR1-FR2-CDR2-FR3-ULCDR3. Also provided are methods ofmaking a humanized antibody variable region sequence comprisingselecting a human antibody variable region sequence comprising asequence encoding FR1-CDR1-FR2-CDR2-FR3; selecting a sequence encoding anon-human ultralong CDR3 (ULCDR3); and genetically fusing the humansequence of step (a) in frame with the non-human sequence of step (b) togenerate a sequence encoding FR1-CDR1-FR2-CDR2-FR3-ULCDR3.

In an embodiment, the present disclosure provides a fusion of a humanVH4 framework sequence to a bovine-derived ultralong CDR3, for example,as may be accomplished through the following steps. First, the secondcysteine of a V region genetic sequence is identified along with thenucleotide sequence encoding the second cysteine. Generally, the secondcysteine marks the boundary of the framework and CDR3 two residuesupstream (N-terminal) of the CDR3. Second, the second cysteine in abovine-derived V region sequence is identified which similarly marks 2residues upstream (N-terminal) of the CDR3. Third, the genetic materialencoding the human V region is combined with the genetic sequenceencoding the ultralong CDR3. Thus, a genetic fusion may be made, whereinthe ultralong CDR3 sequence is placed in frame of the human V regionsequence. Preferably a humanized antibody comprising an ultralong CDR3is as near to human in amino acid composition as possible. Optionally, aJ region sequence may be mutated from bovine-derived sequence to a humansequence. Also optionally, a humanized heavy chain may be paired with ahuman light chain.

In another embodiment, the present disclosure provides pairing of ahuman ultralong CDR3 heavy chain with a non-human light chain.

In another embodiment, the present disclosure provides pairing of ahumanized heavy chain comprising an ultralong CDR3 with a human lightchain. Preferably the light chain is homologous to a bovine light chainknown to pair with a bovine ultralong CDR3 heavy chain. An exemplarybovine light chain is shown in FIG. 7A (e.g., SEQ ID NO: 36-39; and373-376).

Library Methods

The present disclosure provides methods for making libraries comprisinghumanized antibodies comprising ultralong CDR3 sequences. Methods formaking libraries of spatially addressed libraries are described in WO2010/054007. Methods of making libraries in yeast, phage, E. coli, ormammalian cells are well known in the art.

The present disclosure also provides methods of screening libraries ofhumanized antibodies comprising ultralong CDR3 sequences.

DEFINITIONS

An “ultralong CDR3” or an “ultralong CDR3 sequence”, usedinterchangeably herein, comprises a CDR3 or CDR3 sequence that is notderived from a human antibody sequence. An ultralong CDR3 may be 35amino acids in length or longer, for example, 40 amino acids in lengthor longer, 45 amino acids in length or longer, 50 amino acids in lengthor longer, 55 amino acids in length or longer, or 60 amino acids inlength or longer. The length of the ultralong CDR3 may include anon-antibody sequence. An ultralong CDR3 may comprise a non-antibodysequence, including, for example, an interleukin sequence, a hormonesequence, a cytokine sequence, a toxin sequence, a lymphokine sequence,a growth factor sequence, a chemokine sequence, a toxin sequence, orcombinations thereof. Preferably, the ultralong CDR3 is a heavy chainCDR3 (CDR-H3 or CDRH3). Preferably, the ultralong CDR3 is a sequencederived from or based on a ruminant (e.g., bovine) sequence. Anultralong CDR3 may comprise at least 3 or more cysteine residues, forexample, 4 or more cysteine residues, 6 or more cysteine residues, 8 ormore cysteine residues, 10 or more cysteine residues, or 12 or morecysteine residues (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 or more). Anultralong CDR3 may comprise one or more of the following motifs: acysteine motif, a X¹X²X³X⁴X⁵ motif, a CX¹X²X³X⁴X⁵ motif, or a(X^(a)X^(b))_(z) motif. A “cysteine motif” is a segment of amino acidresidues in an ultralong CDR3 that comprises 3 or more cysteine residuesincluding, 4 or more cysteine residues, 5 or more cysteine residues, 6or more cysteine residues, 7 or more cysteine residues, 8 or morecysteine residues, 9 or more cysteine residues, 10 or more cysteineresidues, 11 or more cysteine residues, or 12 or more cysteine residues.A cysteine motif may comprise an amino acid sequence selected from thegroup consisting of:

(SEQ ID NO: 41) CX₁₀CX₅CX₅CXCX₇C, (SEQ ID NO: 42) CX₁₀CX₆CX₅CXCX₁₅C,(SEQ ID NO: 43) CX₁₁CXCX₅C,  (SEQ ID NO: 44) CX₁₁CX₅CX₅CXCX₇C,(SEQ ID NO: 45) CX₁₀CX₆CX₅CXCX₁₃C, (SEQ ID NO: 46) CX₁₀CX₅CXCX₄CX₈C,(SEQ ID NO: 47) CX₁₀CX₆CX₆CXCX₇C, (SEQ ID NO: 48) CX₁₀CX₄CX₇CXCX₈C,(SEQ ID NO: 49) CX₁₀CX₄CX₇CXCX₇C,  (SEQ ID NO: 50) CX₁₃CX₈CX₈C,(SEQ ID NO: 51) CX₁₀CX₆CX₅CXCX₇C,  (SEQ ID NO: 52) CX₁₀CX₅CX₅C,(SEQ ID NO: 53) CX₁₀CX₅CX₆CXCX₇C,  (SEQ ID NO: 54) CX₁₀CX₆CX₅CX₇CX₉C,(SEQ ID NO: 55) CX₉CX₇CX₅CXCX₇C,  (SEQ ID NO: 56) CX₁₉CX₆CX₅CXCX₉C,(SEQ ID NO: 57) CX₁₀CXCX₄CX₅CX₁₁C,  (SEQ ID NO: 58)CX₇CX₃CX₆CX₅CXCX₅CX₁₉C, (SEQ ID NO: 59) CX₁₀CXCX₄CX₅CXCX₂CX₃C, (SEQ ID NO: 60) CX₁₆CX₅CXC, (SEQ ID NO: 61) CX₆CX₄CXCX₄CX₅C, (SEQ ID NO: 62) CX₁₁CX₄CX₅CX₆CX₃C, (SEQ ID NO: 63) CX₈CX₂CX₆CX₅C, (SEQ ID NO: 64) CX₁₀CX₅CX₅CXCX₁₀C, (SEQ ID NO: 65) CX₁₀CXCX₆CX₄CXC, (SEQ ID NO: 66) CX₁₀CX₅CX₅CXCX₂C, (SEQ ID NO: 67) CX₁₄CX₂CX₃CXCXC, (SEQ ID NO: 68) CX₁₅CX₅CXC, (SEQ ID NO: 69) CX₄CX₆CX₉CX₂CX₁₁C, (SEQ ID NO: 70) CX₆CX₄CX₅CX₅CX₁₂C, (SEQ ID NO: 71)CX₇CX₃CXCXCX₄CX₅CX₉C,  (SEQ ID NO: 72) CX₁₉CX₆CX₅C, (SEQ ID NO: 73)CX₇CX₃CX₅CX₅CX₉C,  (SEQ ID NO: 74) CX₇CX₅CXCX₂C,  (SEQ ID NO: 75)CX₁₉CXCX₆C,  (SEQ ID NO: 76) CX₁₀CX₃CX₃CX₅CX₇CXCX₆C,  (SEQ ID NO: 77)CX₁₀CX₄CX₅CX₁₂CX₂C,  (SEQ ID NO: 78) CX₁₂CX₄CX₅CXCXCX₉CX₃C, (SEQ ID NO: 79) CX₁₂CX₄CX₅CX₁₂CX₂C,  (SEQ ID NO: 80) CX₁₉CX₆CX₅CXCX₁₁C, (SEQ ID NO: 81) CX₁₆CX₅CXCXCX₁₄C,  (SEQ ID NO: 82) CX₁₀CX₅CXCX₈CX₆C, (SEQ ID NO: 83) CX₁₂CX₄CX₅CX₈CX₂C, (SEQ ID NO: 84) CX₁₂CX₅CX₅CXCX₈C, (SEQ ID NO: 85) CX₁₀CX₆CX₅CXCX₄CXCX₉C, (SEQ ID NO: 86)CX₁₁CX₄CX₅CX₈CX₂C,  (SEQ ID NO: 87) CX₁₀CX₆CX₅CX₈CX₂C, (SEQ ID NO: 88)CX₁₀CX₆CX₅CXCX₈C,  (SEQ ID NO: 89) CX₁₀CX₆CX₅CXCX₃CX₈CX₂C,(SEQ ID NO: 90) CX₁₀CX₆CX₅CX₃CX₈C,  (SEQ ID NO: 91)CX₁₀CX₆CX₅CXCX₂CX₆CX₅C, (SEQ ID NO: 92) CX₇CX₆CX₃CX₃CX₉C, (SEQ ID NO: 93) CX₉CX₈CX₅CX₆CX₅C, (SEQ ID NO: 94)CX₁₀CX₂CX₂CX₇CXCX₁₁CX₅C,  and  (SEQ ID NO: 95) CX₁₀CX₆CX₅CXCX₂CX₈CX₄C.Alternatively, a cysteine motif may comprise an amino acid sequenceselected from the group consisting of:

(SEQ ID NO: 96) CCX₃CXCX₃CX₂CCXCX₅CX₉CX₅CXC, (SEQ ID NO: 97)CX₆CX₂CX₅CX₄CCXCX₄CX₆CXC,  (SEQ ID NO: 98) CX₇CXCX₅CX₄CCCX₄CX₆CXC,(SEQ ID NO: 99) CX₉CX₃CXCX₂CXCCCX₆CX₄C, (SEQ ID NO: 100)CX₅CX₃CXCX₄CX₄CCX₁₀CX₂CC,  (SEQ ID NO: 101) CX₆CXCX₁CXCX₃CCX₃CX₄CX₁₀C, (SEQ ID NO: 102) CX₉CCCX₃CX₄CCCX₅CX₆C, (SEQ ID NO: 103)CCX₈CX₆CX₄CX₃CX₄CCXCX₁C,  (SEQ ID NO: 104) CCX₆CCX₅CCCX₄CX₄CX₁₂C,(SEQ ID NO: 105) CX₆CX₂CX₃CCCX₄CX₅CX₃CX₃C, (SEQ ID NO: 106)CX₃CX₅CX₆CX₄CCXCX₅CX₄CXC,  (SEQ ID NO: 107) CX₄CX₄CCX₄CX₄CXCX₁₁CX₂CXC, (SEQ ID NO: 108) CX₅CX₂CCX₅CX₄CCX₃CCX₇C, (SEQ ID NO: 109)CX₅CX₅CX₃CX₂CXCCX₄CX₇CXC,  (SEQ ID NO: 110) CX₃CX₇CX₃CX₄CCXCX₂CX₅CX₂C, (SEQ ID NO: 111) CX₉CX₃CXCX₄CCX₅CCCX₆C, (SEQ ID NO: 112)CX₉CX₃CXCX₂CXCCX₆CX₃CX₃C,  (SEQ ID NO: 113) CX₈CCXCX₃CCX₃CXCX₃CX₄C,(SEQ ID NO: 114) CX₉CCX₄CX₂CXCCXCX₄CX₃C, (SEQ ID NO: 115)CX₁₀CXCX₃CX₂CXCCX₄CX₅CXC,  (SEQ ID NO: 116) CX₉CXCX₃CX₂CXCCX₄CX₅CXC,(SEQ ID NO: 117) CX₆CCXCX₅CX₄CCXCX₅CX₂C, (SEQ ID NO: 118)CX₆CCXCX₃CXCCX₃CX₄CC,  (SEQ ID NO: 119) CX₆CCXCX₃CXCX₂CXCX₄CX₈C, (SEQ ID NO: 120) CX₄CX₂CCX₃CXCX₄CCX₂CX₃C,  (SEQ ID NO: 121)CX₃CX₅CX₃CCCX₄CX₉C,  (SEQ ID NO: 122) CCX₉CX₃CXCCX₃CX₅C, (SEQ ID NO: 123) CX₉CX₂CX₃CX₄CCX₄CX₅C,  (SEQ ID NO: 124)CX₉CX₇CX₄CCXCX₇CX₃C,  (SEQ ID NO: 125) CX₉CX₃CCCX₁₀CX₂CX₃C,(SEQ ID NO: 126) CX₃CX₅CX₅CX₄CCX₁₀CX₆C, (SEQ ID NO: 127)CX₉CX₅CX₄CCXCX₅CX₄C,  (SEQ ID NO: 128) CX₇CXCX₆CX₄CCCX₁₉C,(SEQ ID NO: 129) CX₈CX₂CX₄CCX₄CX₃CX₃C, (SEQ ID NO: 130)CX₇CX₅CXCX₄CCX₇CX₄C,  (SEQ ID NO: 131) CX₁₁CX₃CX₄CCCX₈CX₂C, (SEQ ID NO: 132) CX₂CX₃CX₄CCX₄CX₅CX₁₅C,  (SEQ ID NO: 133)CX₉CX₅CX₄CCX₇C,  (SEQ ID NO: 134) CX₉CX₇CX₃CX₂CX₆C, (SEQ ID NO: 135)CX₉CX₅CX₄CCX₁₄C,  (SEQ ID NO: 136) CX₉CX₅CX₄CCX₈C, (SEQ ID NO: 137)CX₉CX₆CX₄CCXC,  (SEQ ID NO: 138) CX₅CCX₇CX₄CX₁₂, (SEQ ID NO: 139)CX₁₀CX₃CX₄CCX₄C,  (SEQ ID NO: 140) CX₉CX₄CCX₅CX₄C, (SEQ ID NO: 141)CX₁₀CX₃CX₄CX₇CXC,  (SEQ ID NO: 142) CX₇CX₇CX₂CX₂CX₃C, (SEQ ID NO: 143)CX₉CX₄CX₄CCX₆C,  (SEQ ID NO: 144) CX₇CXCX₃CXCX₆C, (SEQ ID NO: 145)CX₇CXCX₄CXCX₄C,  (SEQ ID NO: 146) CX₉CX₅CX₄C,  (SEQ ID NO: 147)CX₃CX₆CX₈C,  (SEQ ID NO: 148) CX₁₀CXCX₄C,  (SEQ ID NO: 149) CX₁₀CCX₄C,(SEQ ID NO: 150) CX₁₅C,  (SEQ ID NO: 151) CX₁₀C,  and  (SEQ ID NO: 152)CX₉C.A cysteine motif is preferably positioned within an ultralong CDR3between a X¹X²X³X⁴X⁵ motif and a (X^(a)X^(b))_(z) motif. A “X¹X²X³X⁴X⁵motif” is a series of five consecutive amino acid residues in anultralong CDR3, wherein X¹ is threonine (T), glycine (G), alanine (A),serine (S), or valine (V), wherein X² is serine (S), threonine (T),proline (P), isoleucine (I), alanine (A), valine (V), or asparagine (N),wherein X³ is valine (V), alanine (A), threonine (T), or aspartic acid(D), wherein X⁴ is histidine (H), threonine (T), arginine (R), tyrosine(Y), phenylalanine (F), or leucine (L), and wherein X⁵ is glutamine (Q).In some embodiments, the X¹X²X³X⁴X⁵ motif may be TTVHQ (SEQ ID NO: 153),TSVHQ (SEQ ID NO: 154), SSVTQ (SEQ ID NO: 155), STVHQ (SEQ ID NO: 156),ATVRQ (SEQ ID NO: 157), TTVYQ (SEQ ID NO: 158), SPVHQ (SEQ ID NO: 159),ATVYQ (SEQ ID NO: 160), TAVYQ (SEQ ID NO: 161), TNVHQ (SEQ ID NO: 162),ATVHQ (SEQ ID NO: 163), STVYQ (SEQ ID NO: 164), TIVHQ (SEQ ID NO: 165),AIVYQ (SEQ ID NO: 166), TTVFQ (SEQ ID NO: 167), AAVFQ (SEQ ID NO: 168),GTVHQ (SEQ ID NO: 169), ASVHQ (SEQ ID NO: 170), TAVFQ (SEQ ID NO: 171),ATVFQ (SEQ ID NO: 172), AAAHQ (SEQ ID NO: 173), VVVYQ (SEQ ID NO: 174),GTVFQ (SEQ ID NO: 175), TAVHQ (SEQ ID NO: 176), ITVHQ (SEQ ID NO: 177),ITAHQ (SEQ ID NO: 178), VTVHQ (SEQ ID NO: 179); AAVHQ (SEQ ID NO: 180),GTVYQ (SEQ ID NO: 181), TTVLQ (SEQ ID NO: 182), TTTHQ (SEQ ID NO: 183),or TTDYQ (SEQ ID NO: 184). A “CX¹X²X³X⁴X⁵ motif” is a series of sixconsecutive amino acid residues in an ultralong CDR3, wherein the firstamino acid residue is cysteine, wherein X¹ is threonine (T), glycine(G), alanine (A), serine (S), or valine (V), wherein X² is serine (S),threonine (T), proline (P), isoleucine (I), alanine (A), valine (V), orasparagine (N), wherein X³ is valine (V), alanine (A), threonine (T), oraspartic acid (D), wherein X⁴ is histidine (H), threonine (T), arginine(R), tyrosine (Y), phenylalanine (F), or leucine (L), and wherein X⁵ isglutamine (Q). In some embodiments, the CX¹X²X³X⁴X⁵ motif is CTTVHQ (SEQID NO: 185), CTSVHQ (SEQ ID NO: 186), CSSVTQ (SEQ ID NO: 187), CSTVHQ(SEQ ID NO: 188), CATVRQ (SEQ ID NO: 189), CTTVYQ (SEQ ID NO: 190),CSPVHQ (SEQ ID NO: 191), CATVYQ (SEQ ID NO: 192), CTAVYQ (SEQ ID NO:193), CTNVHQ (SEQ ID NO: 194), CATVHQ (SEQ ID NO: 195), CSTVYQ (SEQ IDNO: 196), CTIVHQ (SEQ ID NO: 197), CAIVYQ (SEQ ID NO: 198), CTTVFQ (SEQID NO: 199), CAAVFQ (SEQ ID NO: 200), CGTVHQ (SEQ ID NO: 201), CASVHQ(SEQ ID NO: 202), CTAVFQ (SEQ ID NO: 203), CATVFQ (SEQ ID NO: 204),CAAAHQ (SEQ ID NO: 205), CVVVYQ (SEQ ID NO: 206), CGTVFQ (SEQ ID NO:207), CTAVHQ (SEQ ID NO: 208), CITVHQ (SEQ ID NO: 209), CITAHQ (SEQ IDNO: 210), CVTVHQ (SEQ ID NO: 211); CAAVHQ (SEQ ID NO: 212), CGTVYQ (SEQID NO: 213), CTTVLQ (SEQ ID NO: 214), CTTTHQ (SEQ ID NO: 215), or CTTDYQ(SEQ ID NO: 216). A “(X^(a)X^(b))_(z)” motif is a repeating series oftwo amino acid residues in an ultralong CDR3, wherein X^(a) is any aminoacid residue, X^(b) is an aromatic amino acid selected from the groupconsisting of: tyrosine (Y), phenylalanine (F), tryptophan (W), andhistidine (H), and wherein z is 1-4. In some embodiments, the(X^(a)X^(b))_(z) motif may comprise CYTYNYEF (SEQ ID NO: 217), HYTYTYDF(SEQ ID NO: 218), HYTYTYEW (SEQ ID NO: 219), KHRYTYEW (SEQ ID NO: 220),NYIYKYSF (SEQ ID NO: 221), PYIYTYQF (SEQ ID NO: 222), SFTYTYEW (SEQ IDNO: 223), SYIYIYQW (SEQ ID NO: 224), SYNYTYSW (SEQ ID NO: 225), SYSYSYEY(SEQ ID NO: 226), SYTYNYDF (SEQ ID NO: 227), SYTYNYEW (SEQ ID NO: 228),SYTYNYQF (SEQ ID NO: 229), SYVWTHNF (SEQ ID NO: 230), TYKYVYEW (SEQ IDNO: 231), TYTYTYEF (SEQ ID NO: 232), TYTYTYEW (SEQ ID NO: 233), VFTYTYEF(SEQ ID NO: 234), AYTYEW (SEQ ID NO: 235), DYIYTY (SEQ ID NO: 236),IHSYEF (SEQ ID NO: 237), SFTYEF (SEQ ID NO: 238), SHSYEF (SEQ ID NO:239), THTYEF (SEQ ID NO: 240), TWTYEF (SEQ ID NO: 241), TYNYEW (SEQ IDNO: 242), TYSYEF (SEQ ID NO: 243), TYSYEH (SEQ ID NO: 244), TYTYDF (SEQID NO: 245), TYTYEF (SEQ ID NO: 246), TYTYEW (SEQ ID NO: 247), AYEF (SEQID NO: 248), AYSF (SEQ ID NO: 249), AYSY (SEQ ID NO: 250), CYSF (SEQ IDNO: 251), DYTY (SEQ ID NO: 252), KYEH (SEQ ID NO: 253), KYEW (SEQ ID NO:254), MYEF (SEQ ID NO: 255), NWIY (SEQ ID NO: 256), NYDY (SEQ ID NO:257), NYQW (SEQ ID NO: 258), NYSF (SEQ ID NO: 259), PYEW (SEQ ID NO:260), RYNW (SEQ ID NO: 261), RYTY (SEQ ID NO: 262), SYEF (SEQ ID NO:263), SYEH (SEQ ID NO: 264), SYEW (SEQ ID NO: 265), SYKW (SEQ ID NO:266), SYTY (SEQ ID NO: 267), TYDF (SEQ ID NO: 268), TYEF (SEQ ID NO:269), TYEW (SEQ ID NO: 270), TYQW (SEQ ID NO: 271), TYTY (SEQ ID NO:272), or VYEW (SEQ ID NO: 273). In some embodiments, the(X^(a)X^(b))_(z) motif is YXYXYX. An ultralong CDR3 may comprise anamino acid sequence that is derived from or based on SEQ ID NO: 40 (see,e.g., amino acid residues 3-6 of SEQ ID NO: 1-4; see also, e.g., VHgermline sequences in FIGS. 2A-C). A variable region that comprises anultralong CDR3 may include an amino acid sequence that is SEQ ID NO: 1(CTTVHQ), SEQ ID NO:2 (CTSVHQ), SEQ ID NO:3 (CSSVTQ) or SEQ ID NO: 4(CTTVHP). Such a sequence may be derived from or based on a bovinegermline VH gene sequence (e.g., SEQ ID NO: 1). An ultralong CDR3 maycomprise a sequence derived from or based on a non-human DH genesequence, for example, SEQ ID NO: 5 (see also, e.g., Koti, et al. (2010)Mol. Immunol. 47: 2119-2128), or alternative sequences such as SEQ IDNO: 6, 7, 8, 9, 10, 11 or 12 (see also, e.g., DH2 germline sequences inFIGS. 2A-C). An ultralong CDR3 may comprise a sequence derived from orbased on a JH sequence, for example, SEQ ID NO: 13 (see also, e.g.,Hosseini, et al. (2004) Int. Immunol. 16: 843-852), or alternativesequences such as SEQ ID NO: 14, 15, 16 or 17 (see also, e.g., JH1germline sequences in FIGS. 2A-C). In an embodiment, an ultralong CDR3may comprise a sequence derived from or based on a non-human VH sequence(e.g., SEQ ID NO: 1, 2, 3 or 4; alternatively VH sequences in FIGS.2A-C) and/or a sequence derived from or based on a non-human DH sequence(e.g., SEQ ID NO: 5, 6, 7, 8, 9, 10, 11 or 12; alternatively DHsequences in FIGS. 2A-C) and/or a sequence derived from or based on a JHsequence (e.g., SEQ ID NO: 13, 14, 15, 16, or 17; alternatively JHsequences in FIGS. 2A-C), and optionally an additional sequencecomprising two to six amino acids or more (e.g., IR, IF, SEQ ID NO: 18,19, 20 or 21) such as, for example, between the VH derived sequence andthe DH derived sequence. In another embodiment, an ultralong CDR3 maycomprise a sequence derived from or based on SEQ ID NO: 22, 23, 24, 25,26, 27, or 28 (see also, e.g., SEQ ID NOs: 276-359 in FIGS. 2A-C).

An “isolated” biological molecule, such as the various polypeptides,polynucleotides, and antibodies disclosed herein, refers to a biologicalmolecule that has been identified and separated and/or recovered from atleast one component of its natural environment.

“Antagonist” refers to any molecule that partially or fully blocks,inhibits, or neutralizes an activity (e.g., biological activity) of apolypeptide. Also encompassed by “antagonist” are molecules that fullyor partially inhibit the transcription or translation of mRNA encodingthe polypeptide. Suitable antagonist molecules include, e.g., antagonistantibodies or antibody fragments; fragments or amino acid sequencevariants of a native polypeptide; peptides; antisense oligonucleotides;small organic molecules; and nucleic acids that encode polypeptideantagonists or antagonist antibodies. Reference to “an” antagonistencompasses a single antagonist or a combination of two or moredifferent antagonists.

“Agonist” refers to any molecule that partially or fully mimics abiological activity of a polypeptide. Also encompassed by “agonist” aremolecules that stimulate the transcription or translation of mRNAencoding the polypeptide. Suitable agonist molecules include, e.g.,agonist antibodies or antibody fragments; a native polypeptide;fragments or amino acid sequence variants of a native polypeptide;peptides; antisense oligonucleotides; small organic molecules; andnucleic acids that encode polypeptides agonists or antibodies. Referenceto “an” agonist encompasses a single agonist or a combination of two ormore different agonists.

An “isolated” antibody refers to one which has been identified andseparated and/or recovered from a component of its natural environment.Contaminant components of its natural environment are materials whichwould interfere with diagnostic or therapeutic uses for the antibody,and may include enzymes, hormones, and other proteinaceous ornonproteinaceous solutes. In preferred embodiments, the antibody will bepurified (1) to greater than 95% by weight of antibody (e.g., asdetermined by the Lowry method), and preferably to more than 99% byweight, (2) to a degree sufficient to obtain at least 15 residues ofN-terminal or internal amino acid sequence (e.g., by use of a spinningcup sequenator), or (3) to homogeneity by SDS-PAGE under reducing ornonreducing conditions (e.g., using Coomassie™ blue or, preferably,silver stain). Isolated antibody includes the antibody in situ withinrecombinant cells since at least one component of the antibody's naturalenvironment will not be present. Similarly, isolated antibody includesthe antibody in medium around recombinant cells. An isolated antibodymay be prepared by at least one purification step.

An “isolated” nucleic acid molecule refers to a nucleic acid moleculethat is identified and separated from at least one contaminant nucleicacid molecule with which it is ordinarily associated in the naturalsource of the antibody nucleic acid. An isolated nucleic acid moleculeis other than in the form or setting in which it is found in nature.Isolated nucleic acid molecules therefore are distinguished from thenucleic acid molecule as it exists in natural cells. However, anisolated nucleic acid molecule includes a nucleic acid moleculecontained in cells that express an antibody where, for example, thenucleic acid molecule is in a chromosomal location different from thatof natural cells.

Variable domain residue numbering as in Kabat or amino acid positionnumbering as in Kabat, and variations thereof, refers to the numberingsystem used for heavy chain variable domains or light chain variabledomains of the compilation of antibodies in Kabat et al., Sequences ofProteins of Immunological Interest, 5th Ed. Public Health Service,National Institutes of Health, Bethesda, Md. (1991). Using thisnumbering system, the actual linear amino acid sequence may containfewer or additional amino acids corresponding to a shortening of, orinsertion into, a FR or CDR of the variable domain. For example, a heavychain variable domain may include a single amino acid insert (e.g.,residue 52a according to Kabat) after residue 52 of H2 and insertedresidues (e.g., residues 82a, 82b, and 82c, etc according to Kabat)after heavy chain FR residue 82. The Kabat numbering of residues may bedetermined for a given antibody by alignment at regions of homology ofthe sequence of the antibody with a “standard” Kabat numbered sequence.

“Substantially similar,” or “substantially the same”, refers to asufficiently high degree of similarity between two numeric values(generally one associated with an antibody disclosed herein and theother associated with a reference/comparator antibody) such that one ofskill in the art would consider the difference between the two values tobe of little or no biological and/or statistical significance within thecontext of the biological characteristic measured by said values (e.g.,Kd values). The difference between said two values is preferably lessthan about 50%, preferably less than about 40%, preferably less thanabout 30%, preferably less than about 20%, preferably less than about10% as a function of the value for the reference/comparator antibody.

“Binding affinity” generally refers to the strength of the sum total ofnoncovalent interactions between a single binding site of a molecule(e.g., an antibody) and its binding partner (e.g., an antigen). Unlessindicated otherwise, “binding affinity” refers to intrinsic bindingaffinity which reflects a 1:1 interaction between members of a bindingpair (e.g., antibody and antigen). The affinity of a molecule X for itspartner Y can generally be represented by the dissociation constant.Affinity can be measured by common methods known in the art, includingthose described herein. Low-affinity antibodies generally bind antigenslowly and tend to dissociate readily, whereas high-affinity antibodiesgenerally bind antigen faster and tend to remain bound longer. A varietyof methods of measuring binding affinity are known in the art, any ofwhich can be used for purposes of the present disclosure.

An “on-rate” or “rate of association” or “association rate” or “k_(on)”can be determined with a surface plasmon resonance technique such asBiacore (e.g., Biacore A100, Biacore™-2000, Biacore™-3000, Biacore,Inc., Piscataway, N.J.) carboxymethylated dextran biosensor chips (CM5,Biacore Inc.) and according to the supplier's instructions.

“Vector” refers to a nucleic acid molecule capable of transportinganother nucleic acid to which it has been linked. One type of vector isa “plasmid”, which refers to a circular double stranded DNA loop intowhich additional DNA segments may be ligated. Another type of vector isa phage vector. Another type of vector is a viral vector, whereinadditional DNA segments may be ligated into the viral genome. Certainvectors are capable of autonomous replication in a host cell into whichthey are introduced (e.g., bacterial vectors having a bacterial originof replication and episomal mammalian vectors). Other vectors (e.g.,non-episomal mammalian vectors) can be integrated into the genome of ahost cell upon introduction into the host cell, and thereby arereplicated along with the host genome. Moreover, certain vectors arecapable of directing the expression of genes to which they areoperatively linked. Such vectors are referred to herein as “recombinantexpression vectors” (or simply, “recombinant vectors”). In general,expression vectors of utility in recombinant DNA techniques are often inthe form of plasmids. Accordingly, “plasmid” and “vector” may, at times,be used interchangeably as the plasmid is a commonly used form ofvector.

“Gene” refers to a nucleic acid (e.g., DNA) sequence that comprisescoding sequences necessary for the production of a polypeptide,precursor, or RNA (e.g., rRNA, tRNA). The polypeptide can be encoded bya full length coding sequence or by any portion of the coding sequenceso long as the desired activity or functional properties (e.g.,enzymatic activity, ligand binding, signal transduction, immunogenicity,etc.) of the full-length or fragment are retained. The term alsoencompasses the coding region of a structural gene and the sequenceslocated adjacent to the coding region on both the 5′ and 3′ ends for adistance of about 1 kb or more on either end such that the genecorresponds to the length of the full-length mRNA. Sequences located 5′of the coding region and present on the mRNA are referred to as 5′non-translated sequences. Sequences located 3′ or downstream of thecoding region and present on the mRNA are referred to as 3′non-translated sequences. The term “gene” encompasses both cDNA andgenomic forms of a gene. A genomic form or clone of a gene contains thecoding region interrupted with non-coding sequences termed “introns” or“intervening regions” or “intervening sequences.” Introns are segmentsof a gene that are transcribed into nuclear RNA (hnRNA); introns cancontain regulatory elements such as enhancers. Introns are removed or“spliced out” from the nuclear or primary transcript; introns thereforeare absent in the messenger RNA (mRNA) transcript. The mRNA functionsduring translation to specify the sequence or order of amino acids in anascent polypeptide. In addition to containing introns, genomic forms ofa gene can also include sequences located on both the 5′ and 3′ end ofthe sequences that are present on the RNA transcript. These sequencesare referred to as “flanking” sequences or regions (these flankingsequences are located 5′ or 3′ to the non-translated sequences presenton the mRNA transcript). The 5′ flanking region can contain regulatorysequences such as promoters and enhancers that control or influence thetranscription of the gene. The 3′ flanking region can contain sequencesthat direct the termination of transcription, post transcriptionalcleavage and polyadenylation.

“Polynucleotide,” or “nucleic acid,” as used interchangeably herein,refers to polymers of nucleotides of any length, and include DNA andRNA. The nucleotides can be deoxyribonucleotides, ribonucleotides,modified nucleotides or bases, and/or their analogs, or any substratethat can be incorporated into a polymer by DNA or RNA polymerase, or bya synthetic reaction. A polynucleotide may comprise modifiednucleotides, such as methylated nucleotides and their analogs. Ifpresent, modification to the nucleotide structure may be imparted beforeor after assembly of the polymer. The sequence of nucleotides may beinterrupted by non-nucleotide components. A polynucleotide may befurther modified after synthesis, such as by conjugation with a label.Other types of modifications include, for example, “caps”, substitutionof one or more of the naturally occurring nucleotides with an analog,internucleotide modifications such as, for example, those with unchargedlinkages (e.g., methyl phosphonates, phosphotriesters, phosphoamidates,carbamates, etc.) and with charged linkages (e.g., phosphorothioates,phosphorodithioates, etc.), those containing pendant moieties, such as,for example, proteins (e.g., nucleases, toxins, antibodies, signalpeptides, poly-L-lysine, etc.), those with intercalators (e.g.,acridine, psoralen, etc.), those containing chelators (e.g., metals,radioactive metals, boron, oxidative metals, etc.), those containingalkylators, those with modified linkages (e.g., alpha anomeric nucleicacids, etc.), as well as unmodified forms of the polynucleotide(s).Further, any of the hydroxyl groups ordinarily present in the sugars maybe replaced, for example, by phosphonate groups, phosphate groups,protected by standard protecting groups, or activated to prepareadditional linkages to additional nucleotides, or may be conjugated tosolid or semi-solid supports. The 5′ and 3′ terminal OH can bephosphorylated or substituted with amines or organic capping groupmoieties of from 1 to 20 carbon atoms. Other hydroxyls may also bederivatized to standard protecting groups. Polynucleotides can alsocontain analogous forms of ribose or deoxyribose sugars that aregenerally known in the art, including, for example, 2′-O-methyl-,2′-O-allyl, 2′-fluoro- or 2′-azido-ribose, carbocyclic sugar analogs,alpha-anomeric sugars, epimeric sugars such as arabinose, xyloses orlyxoses, pyranose sugars, furanose sugars, sedoheptuloses, acyclicanalogs and a basic nucleoside analogs such as methyl riboside. One ormore phosphodiester linkages may be replaced by alternative linkinggroups. These alternative linking groups include, but are not limitedto, embodiments wherein phosphate is replaced by P(O)S(“thioate”), P(S)S(“dithioate”), “(O)NR₂ (“amidate”), P(O)R, P(O)OR′, CO or CH₂(“formacetal”), in which each R or R′ is independently H or substitutedor unsubstituted alkyl (1-20 C) optionally containing an ether (—O—)linkage, aryl, alkenyl, cycloalkyl, cycloalkenyl or araldyl. Not alllinkages in a polynucleotide need be identical. The precedingdescription applies to all polynucleotides referred to herein, includingRNA and DNA.

“Oligonucleotide” refers to short, generally single stranded, generallysynthetic polynucleotides that are generally, but not necessarily, lessthan about 200 nucleotides in length. The terms “oligonucleotide” and“polynucleotide” are not mutually exclusive. The description above forpolynucleotides is equally and fully applicable to oligonucleotides.

“Stringent hybridization conditions” refer to conditions under which aprobe will hybridize to its target subsequence, typically in a complexmixture of nucleic acids, but to no other sequences. Stringentconditions are sequence-dependent and will be different in differentcircumstances. Longer sequences hybridize specifically at highertemperatures. An extensive guide to the hybridization of nucleic acidsis found in Tijssen, Techniques in Biochemistry and MolecularBiology—Hybridization with Nucleic Probes, “Overview of principles ofhybridization and the strategy of nucleic acid assays” (1993).Generally, stringent conditions are selected to be about 5-10° C. lowerthan the thermal melting point (Tm) for the specific sequence at adefined ionic strength pH. The Tm is the temperature (under definedionic strength, pH, and nucleic concentration) at which 50% of theprobes complementary to the target hybridize to the target sequence atequilibrium (as the target sequences are present in excess, at Tm, 50%of the probes are occupied at equilibrium). Stringent conditions mayalso be achieved with the addition of destabilizing agents such asformamide. For selective or specific hybridization, a positive signal isat least two times background, preferably 10 times backgroundhybridization. Exemplary stringent hybridization conditions can be asfollowing: 50% formamide, 5×SSC, and 1% SDS, incubating at 42° C., or,5×SSC, 1% SDS, incubating at 65° C., with wash in 0.2×SSC, and 0.1% SDSat 65° C.

“Recombinant” when used with reference to a cell, nucleic acid, proteinor vector indicates that the cell, nucleic acid, protein or vector hasbeen modified by the introduction of a heterologous nucleic acid orprotein, the alteration of a native nucleic acid or protein, or that thecell is derived from a cell so modified. For example, recombinant cellsexpress genes that are not found within the native (non-recombinant)form of the cell or express native genes that are overexpressed orotherwise abnormally expressed such as, for example, expressed asnon-naturally occurring fragments or splice variants. By the term“recombinant nucleic acid” herein is meant nucleic acid, originallyformed in vitro, in general, by the manipulation of nucleic acid, e.g.,using polymerases and endonucleases, in a form not normally found innature. In this manner, operably linkage of different sequences isachieved. Thus an isolated nucleic acid, in a linear form, or anexpression vector formed in vitro by ligating DNA molecules that are notnormally joined, are both considered recombinant for the purposes ofthis disclosure. It is understood that once a recombinant nucleic acidis made and introduced into a host cell or organism, it will replicatenon-recombinantly, e.g., using the in vivo cellular machinery of thehost cell rather than in vitro manipulations; however, such nucleicacids, once produced recombinantly, although subsequently replicatednon-recombinantly, are still considered recombinant for the purposesdisclosed herein. Similarly, a “recombinant protein” is a protein madeusing recombinant techniques, e.g., through the expression of arecombinant nucleic acid as depicted above.

“Percent (%) amino acid sequence identity” with respect to a peptide orpolypeptide sequence refers to the percentage of amino acid residues ina candidate sequence that are identical with the amino acid residues inthe specific peptide or polypeptide sequence, after aligning thesequences and introducing gaps, if necessary, to achieve the maximumpercent sequence identity, and not considering any conservativesubstitutions as part of the sequence identity. Alignment for purposesof determining percent amino acid sequence identity can be achieved invarious ways that are within the skill in the art, for instance, usingpublicly available computer software such as BLAST, BLAST-2, ALIGN orMegAlign (DNASTAR) software. Those skilled in the art can determineappropriate parameters for measuring alignment, including any algorithmsneeded to achieve maximal alignment over the full length of thesequences being compared.

“Polypeptide,” “peptide,” “protein,” and “protein fragment” may be usedinterchangeably to refer to a polymer of amino acid residues. The termsapply to amino acid polymers in which one or more amino acid residue isan artificial chemical mimetic of a corresponding naturally occurringamino acid, as well as to naturally occurring amino acid polymers andnon-naturally occurring amino acid polymers.

“Amino acid” refers to naturally occurring and synthetic amino acids, aswell as amino acid analogs and amino acid mimetics that functionsimilarly to the naturally occurring amino acids. Naturally occurringamino acids are those encoded by the genetic code, as well as thoseamino acids that are later modified, e.g., hydroxyproline,gamma-carboxyglutamate, and O-phosphoserine. Amino acid analogs refersto compounds that have the same basic chemical structure as a naturallyoccurring amino acid, e.g., an alpha carbon that is bound to a hydrogen,a carboxyl group, an amino group, and an R group, e.g., homoserine,norleucine, methionine sulfoxide, methionine methyl sulfonium. Suchanalogs can have modified R groups (e.g., norleucine) or modifiedpeptide backbones, but retain the same basic chemical structure as anaturally occurring amino acid. Amino acid mimetics refers to chemicalcompounds that have a structure that is different from the generalchemical structure of an amino acid, but that functions similarly to anaturally occurring amino acid.

“Conservatively modified variants” applies to both amino acid andnucleic acid sequences. “Amino acid variants” refers to amino acidsequences. With respect to particular nucleic acid sequences,conservatively modified variants refers to those nucleic acids whichencode identical or essentially identical amino acid sequences, or wherethe nucleic acid does not encode an amino acid sequence, to essentiallyidentical or associated (e.g., naturally contiguous) sequences. Becauseof the degeneracy of the genetic code, a large number of functionallyidentical nucleic acids encode most proteins. For instance, the codonsGCA, GCC, GCG and GCU all encode the amino acid alanine. Thus, at everyposition where an alanine is specified by a codon, the codon can bealtered to another of the corresponding codons described withoutaltering the encoded polypeptide. Such nucleic acid variations are“silent variations,” which are one species of conservatively modifiedvariations. Every nucleic acid sequence herein which encodes apolypeptide also describes silent variations of the nucleic acid. One ofskill will recognize that in certain contexts each codon in a nucleicacid (except AUG, which is ordinarily the only codon for methionine, andTGG, which is ordinarily the only codon for tryptophan) can be modifiedto yield a functionally identical molecule. Accordingly, silentvariations of a nucleic acid which encodes a polypeptide is implicit ina described sequence with respect to the expression product, but notwith respect to actual probe sequences. As to amino acid sequences, oneof skill will recognize that individual substitutions, deletions oradditions to a nucleic acid, peptide, polypeptide, or protein sequencewhich alters, adds or deletes a single amino acid or a small percentageof amino acids in the encoded sequence is a “conservatively modifiedvariant” including where the alteration results in the substitution ofan amino acid with a chemically similar amino acid. Conservativesubstitution tables providing functionally similar amino acids are wellknown in the art. Such conservatively modified variants are in additionto and do not exclude polymorphic variants, interspecies homologs, andalleles disclosed herein. Typically conservative substitutionsinclude: 1) Alanine (A), Glycine (G); 2) Aspartic acid (D), Glutamicacid (E); 3) Asparagine (N), Glutamine (Q); 4) Arginine (R), Lysine (K);5) Isoleucine (I), Leucine (L), Methionine (M), Valine (V);6)Phenylalanine (F), Tyrosine (Y), Tryptophan (W); 7) Serine (S),Threonine (T); and 8) Cysteine (C), Methionine (M) (see, e.g.,Creighton, Proteins (1984)).

“Antibodies” (Abs) and “immunoglobulins” (Igs) are glycoproteins havingsimilar structural characteristics. While antibodies may exhibit bindingspecificity to a specific antigen, immunoglobulins may include bothantibodies and other antibody-like molecules which generally lackantigen specificity. Polypeptides of the latter kind are, for example,produced at low levels by the lymph system and at increased levels bymyelomas.

“Antibody” and “immunoglobulin” are used interchangeably in the broadestsense and include monoclonal antibodies (e.g., full length or intactmonoclonal antibodies), polyclonal antibodies, multivalent antibodies,multispecific antibodies (e.g., bispecific antibodies so long as theyexhibit the desired biological activity) and may also include certainantibody fragments (as described in greater detail herein). An antibodycan be human, humanized and/or affinity matured. An antibody may referto immunoglobulins and immunoglobulin portions, whether natural orpartially or wholly synthetic, such as recombinantly produced, includingany portion thereof containing at least a portion of the variable regionof the immunoglobulin molecule that is sufficient to form an antigenbinding site. Hence, an antibody or portion thereof includes any proteinhaving a binding domain that is homologous or substantially homologousto an immunoglobulin antigen binding site. For example, an antibody mayrefer to an antibody that contains two heavy chains (which can bedenoted H and H′) and two light chains (which can be denoted L and L′),where each heavy chain can be a full-length immunoglobulin heavy chainor a portion thereof sufficient to form an antigen binding site (e.g.heavy chains include, but are not limited to, VH, chains VH-CH1 chainsand VH-CH1-CH2-CH3 chains), and each light chain can be a full-lengthlight chain or a thereof sufficient to form an antigen binding site(e.g. light chains include, but are not limited to, VL chains and VL-CLchains). Each heavy chain (H and H′) pairs with one light chain (L andL′, respectively). Typically, antibodies minimally include all or atleast a portion of the variable heavy (VH) chain and/or the variablelight (VL) chain. The antibody also can include all or a portion of theconstant region. For example, a full-length antibody is an antibodyhaving two full-length heavy chains (e.g. VH-CH1-CH2-CH3 orVH-CH1-CH2-CH3-CH4) and two full-length light chains (VL-CL) and hingeregions, such as antibodies produced by antibody secreting B cells andantibodies with the same domains that are produced synthetically.Additionally, an “antibody” refers to a protein of the immunoglobulinfamily or a polypeptide comprising fragments of an immunoglobulin thatis capable of noncovalently, reversibly, and in a specific mannerbinding a corresponding antigen. An exemplary antibody structural unitcomprises a tetramer. Each tetramer is composed of two identical pairsof polypeptide chains, each pair having one “light” (about 25 kD) andone “heavy” chain (about 50-70 kD), connected through a disulfide bond.The recognized immunoglobulin genes include the κ, λ, α, γ, δ, ε, and μconstant region genes, as well as the myriad immunoglobulin variableregion genes. Light chains are classified as either κ or λ. Heavy chainsare classified as γ, μ, α, δ, or ε, which in turn define theimmunoglobulin classes, IgG, IgM, IgA, IgD, and IgE, respectively. TheN-terminus of each chain defines a variable region of about 100 to 110or more amino acids primarily responsible for antigen recognition. Theterms variable light chain (VL) and variable heavy chain (VH) refer tothese regions of light and heavy chains respectively.

“Variable” refers to the fact that certain portions of the variabledomains (also referred to as variable regions) differ extensively insequence among antibodies and are used in the binding and specificity ofeach particular antibody for its particular antigen. However, thevariability is not evenly distributed throughout the variable domains ofantibodies. It is concentrated in three segments calledcomplementarity-determining regions (CDRs) or hypervariable regions(HVRs) both in the light-chain and the heavy-chain variable domains.CDRs include those specified as Kabat, Chothia, and IMGT as shown hereinwithin the variable region sequences. The more highly conserved portionsof variable domains are called the framework (FR). The variable domainsof native heavy and light chains each comprise four FR regions, largelyadopting a β-sheet configuration, connected by three CDRs, which formloops connecting, and in some cases forming part of, the β-sheetstructure. The CDRs in each chain are held together in close proximityby the FR regions and, with the CDRs from the other chain, contribute tothe formation of the antigen-binding site of antibodies (see Kabat etal., Sequences of Proteins of Immunological Interest, Fifth Edition,National Institute of Health, Bethesda, Md. (1991)). The constantdomains are not involved directly in binding an antibody to an antigen,but exhibit various effector functions, such as participation of theantibody in antibody-dependent cellular toxicity.

Papain digestion of antibodies produces two identical antigen-bindingfragments, called “Fab” fragments, each with a single antigen-bindingsite, and a residual “Fc” fragment, whose name reflects its ability tocrystallize readily. Pepsin treatment yields an F(ab′)₂ fragment thathas two antigen-combining sites and is still capable of cross-linkingantigen.

“Fv” refers to an antibody fragment which contains anantigen-recognition and antigen-binding site. In a two-chain Fv species,this region consists of a dimer of one heavy and one light chainvariable domain in non-covalent association. In a single chain Fv (scFv)species, one heavy chain and one light chain variable domain can becovalently linked by a flexible peptide linker such that the light andheavy chains can associate in a “dimeric” structure analogous to that ina two-chain Fv (scFv) species. It is in this configuration that thethree CDRs of each variable domain interact to define an antigen-bindingsite on the surface of the VH-VL dimer. Collectively, the six CDRsconfer antigen-binding specificity to the antibody. However, even asingle variable domain (or half of an Fv comprising only three CDRsspecific for an antigen) has the ability to recognize and bind antigen,although at a lower affinity than the entire binding site.

The Fab fragment also contains the constant domain of the light chainand the first constant domain (CHI) of the heavy chain. Fab′ fragmentsdiffer from Fab fragments by the addition of a few residues at thecarboxy terminus of the heavy chain CH1 domain including one or morecysteines from the antibody hinge region. Fab′-SH is the designationherein for Fab′ in which the cysteine residue(s) of the constant domainsbear a free thiol group. F(ab′)₂ antibody fragments originally wereproduced as pairs of Fab′ fragments which have hinge cysteines betweenthem. Other chemical couplings of antibody fragments are also known.

The “light chains” of antibodies (immunoglobulins) from any vertebratespecies can be assigned to one of two clearly distinct types, calledkappa (K) and lambda (A), based on the amino acid sequences of theirconstant domains.

Depending on the amino acid sequence of the constant domain of theirheavy chains, immunoglobulins can be assigned to different classes.There are five major classes of immunoglobulins: IgA, IgD, IgE, IgG, andIgM, and several of these can be further divided into subclasses(isotypes), e.g., IgG₁, IgG₂, IgG₃, IgG₄, IgA₁, and IgA₂. Theheavy-chain constant domains that correspond to the different classes ofimmunoglobulins are called α, δ, ε, γ, and μ, respectively. The subunitstructures and three-dimensional configurations of different classes ofimmunoglobulins are well known.

“Antibody fragments” comprise only a portion of an intact antibody,wherein the portion preferably retains at least one, preferably most orall, of the functions normally associated with that portion when presentin an intact antibody. Examples of antibody fragments include Fab, Fab′,F(ab′)2, single-chain Fvs (scFv), Fv, dsFv, diabody, Fd and Fd′fragments Fab fragments, Fd fragments, scFv fragments, linearantibodies, single-chain antibody molecules, and multispecificantibodies formed from antibody fragments (see, for example, Methods inMolecular Biology, Vol 207: Recombinant Antibodies for Cancer TherapyMethods and Protocols (2003); Chapter 1; p 3-25, Kipriyanov). Otherknown fragments include, but are not limited to, scFab fragments (Hustet al., BMC Biotechnology (2007), 7:14). In one embodiment, an antibodyfragment comprises an antigen binding site of the intact antibody andthus retains the ability to bind antigen. In another embodiment, anantibody fragment, for example one that comprises the Fc region, retainsat least one of the biological functions normally associated with the Fcregion when present in an intact antibody, such as FcRn binding,antibody half life modulation, ADCC function and complement binding. Inone embodiment, an antibody fragment is a monovalent antibody that hasan in vivo half life substantially similar to an intact antibody. Forexample, such an antibody fragment may comprise on antigen binding armlinked to an Fc sequence capable of conferring in vivo stability to thefragment. For another example, an antibody fragment or antibody portionrefers to any portion of a full-length antibody that is less than fulllength but contains at least a portion of the variable region of theantibody sufficient to form an antigen binding site (e.g. one or moreCDRs) and thus retains the a binding specificity and/or an activity ofthe full-length antibody; antibody fragments include antibodyderivatives produced by enzymatic treatment of full-length antibodies,as well as synthetically, e.g. recombinantly produced derivatives.

A “dsFv” refers to an Fv with an engineered intermolecular disulfidebond, which stabilizes the VH-VL pair.

A “Fd fragment” refers to a fragment of an antibody containing avariable domain (VH) and one constant region domain (CH1) of an antibodyheavy chain.

A “Fab fragment” refers to an antibody fragment that contains theportion of the full-length antibody that would results from digestion ofa full-length immunoglobulin with papain, or a fragment having the samestructure that is produced synthetically, e.g. recombinantly. A Fabfragment contains a light chain (containing a VL and CL portion) andanother chain containing a variable domain of a heavy chain (VH) and oneconstant region domain portion of the heavy chain (CH1); it can berecombinantly produced.

A “F(ab′)2 fragment” refers to an antibody fragment that results fromdigestion of an immunoglobulin with pepsin at pH 4.0-4.5, or asynthetically, e.g. recombinantly, produced antibody having the samestructure. The F(ab′)2 fragment contains two Fab fragments but whereeach heavy chain portion contains an additional few amino acids,including cysteine residues that form disulfide linkages joining the twofragments; it can be recombinantly produced.

A “Fab′ fragment” refers to a fragment containing one half (one heavychain and one light chain) of the F(ab′)2 fragment.

A “Fd′ fragment refers to a fragment of an antibody containing one heavychain portion of a F(ab′)2 fragment.

A “Fv′ fragment” refers to a fragment containing only the VH and VLdomains of an antibody molecule.

A “scFv fragment” refers to an antibody fragment that contains avariable light chain (VL) and variable heavy chain (VH), covalentlyconnected by a polypeptide linker in any order. The linker is of alength such that the two variable domains are bridged withoutsubstantial interference. Exemplary linkers are (Gly-Ser)n residues withsome Glu or Lys residues dispersed throughout to increase solubility.

Diabodies are dimeric scFv; diabodies typically have shorter peptidelinkers than scFvs, and they preferentially dimerize.

“HsFv” refers to antibody fragments in which the constant domainsnormally present in a Fab fragment have been substituted with aheterodimeric coiled-coil domain (see, e.g., Arndt et al. (2001) J MolBiol. 7:312:221-228).

“Hypervariable region”, “HVR”, or “HV”, as well as “complementarydetermining region” or “CDR”, may refer to the regions of an antibodyvariable domain which are hypervariable in sequence and/or formstructurally defined loops. Generally, antibodies comprise sixhypervariable or CDR regions; three in the VH (H1, H2, H3), and three inthe VL (L1, L2, L3). A number of hypervariable region or CDRdelineations are in use and are encompassed herein. The KabatComplementarity Determining Regions (Kabat CDRs) are based on sequencevariability and are the most commonly used (Kabat et al., Sequences ofProteins of Immunological Interest, 5th Ed. Public Health Service,National Institutes of Health, Bethesda, Md. (1991)). Chothia refersinstead to the location of the structural loops (Chothia and Lesk, J.Mol. Biol. 196:901-917 (1987)). The AbM hypervariable regions representa compromise between the Kabat CDRs and Chothia structural loops,(Chothia “CDRs”) and are used by Oxford Molecular's AbM antibodymodeling software. The “contact” hypervariable regions are based on ananalysis of the available complex crystal structures. The residues fromeach of these hypervariable regions are noted below.

Loop Kabat AbM Chothia Contact L1 L24-L34 L24-L34 L26-L32 L30-L36 L2L50-L56 L50-L56 L50-L52 L46-L55 L3 L89-L97 L89-L97 L91-L96 L89-L96 H1H31-H35B H26-H35B H26-H32 H30-H35B (Kabat Numbering) H1 H31-H35 H26-H35H26-H32 H30-H35 (Chothia Numbering) H2 H50-H65 H50-H58 H53-H55 H47-H58H3 H95-H102 H95-H102 H96-H101 H93-H101IMGT refers to the international ImMunoGeneTics Information System, asdescribed by Lefrace et al., Nucl. Acids, Res. 37; D1006-D1012 (2009),including for example, IMGT designated CDRs for antibodies.

Hypervariable regions may comprise “extended hypervariable regions” asfollows: 24-36 or 24-34 (L1), 46-56 or 50-56 (L2) and 89-97 (L3) in theVL and 26-35 (H1), 50-65 or 49-65 (H2) and 93-102, 94-102 or 95-102 (H3)in the VH. The variable domain residues are numbered according to Kabatet al., Supra for each of these definitions.

“Framework” or “FR” residues are those variable domain residues otherthan the hypervariable region residues as herein defined. “Frameworkregions” (FRs) are the domains within the antibody variable regiondomains comprising framework residues that are located within the betasheets; the FR regions are comparatively more conserved, in terms oftheir amino acid sequences, than the hypervariable regions.

“Monoclonal antibody” refers to an antibody from a population ofsubstantially homogeneous antibodies, that is, for example, theindividual antibodies comprising the population are identical and/orbind the same epitope(s), except for possible variants that may ariseduring production of the monoclonal antibody, such variants generallybeing present in minor amounts. Such monoclonal antibody typicallyincludes an antibody comprising a polypeptide sequence that binds atarget, wherein the target-binding polypeptide sequence was obtained bya process that includes the selection of a single target bindingpolypeptide sequence from a plurality of polypeptide sequences. Forexample, the selection process can be the selection of a unique clonefrom a plurality of clones, such as a pool of hybridoma clones, phageclones or recombinant DNA clones. It should be understood that theselected target binding sequence can be further altered, for example, toimprove affinity for the target, to humanize the target bindingsequence, to improve its production in cell culture, to reduce itsimmunogenicity in vivo, to create a multispecific antibody, etc., andthat an antibody comprising the altered target binding sequence is alsoa monoclonal antibody of this disclosure. In contrast to polyclonalantibody preparations which typically include different antibodiesdirected against different determinants (e.g., epitopes), eachmonoclonal antibody of a monoclonal antibody preparation is directedagainst a single determinant on an antigen. In addition to theirspecificity, the monoclonal antibody preparations are advantageous inthat they are typically uncontaminated by other immunoglobulins. Themodifier “monoclonal” indicates the character of the antibody as beingobtained from a substantially homogeneous population of antibodies, andis not to be construed as requiring production of the antibody by anyparticular method. For example, the monoclonal antibodies to be used inaccordance with the present disclosure may be made by a variety oftechniques, including, for example, the hybridoma method (e.g., Kohleret al., Nature, 256:495 (1975); Harlow et al., Antibodies: A LaboratoryManual, (Cold Spring Harbor Laboratory Press, 2nd ed. 1988); Hammerlinget al., in: Monoclonal Antibodies and T-Cell Hybridomas 563-681,(Elsevier, N.Y., 1981)), recombinant DNA methods (see, e.g., U.S. Pat.No. 4,816,567), phage display technologies (see, e.g., Clackson et al.,Nature, 352:624-628 (1991); Marks et al., J. Mol. Biol., 222:581-597(1991); Sidhu et al., J. Mol. Biol. 338(2):299-310 (2004); Lee et al.,J. Mol. Biol. 340(5):1073-1093 (2004); Fellouse, Proc. Nat. Acad. Sci.USA 101(34):12467-12472 (2004); and Lee et al. J. Immunol. Methods284(1-2):119-132 (2004), and technologies for producing human orhuman-like antibodies in animals that have parts or all of the humanimmunoglobulin loci or genes encoding human immunoglobulin sequences(see, e.g., WO 1998/24893; WO 1996/34096; WO 1996/33735; WO 1991/10741;Jakobovits et al., Proc. Natl. Acad. Sci. USA, 90:2551 (1993);Jakobovits et al., Nature, 362:255-258 (1993); Bruggemann et al., Yearin Immuno., 7:33 (1993); U.S. Pat. Nos. 5,545,806; 5,569,825; 5,591,669;5,545,807; WO 1997/17852; U.S. Pat. Nos. 5,545,807; 5,545,806;5,569,825; 5,625,126; 5,633,425; and U.S. Pat. No. 5,661,016; Marks etal., Bio/Technology, 10: 779-783 (1992); Lonberg et al., Nature, 368:856-859 (1994); Morrison, Nature, 368: 812-813 (1994); Fishwild et al.,Nature Biotechnology, 14: 845-851 (1996); Neuberger, NatureBiotechnology, 14: 826 (1996); and Lonberg and Huszar, Intern. Rev.Immunol., 13: 65-93 (1995)).

“Humanized” or “Human engineered” forms of non-human (e.g., murine)antibodies are chimeric antibodies that contain amino acids representedin human immunoglobulin sequences, including, for example, whereinminimal sequence is derived from non-human immunoglobulin. For example,humanized antibodies may be human antibodies in which some hypervariableregion residues and possibly some FR residues are substituted byresidues from analogous sites in non-human (e.g., rodent) antibodies.Alternatively, humanized or human engineered antibodies may be non-human(e.g., rodent) antibodies in which some residues are substituted byresidues from analogous sites in human antibodies (see, e.g., U.S. Pat.No. 5,766,886). Humanized antibodies include human immunoglobulins(recipient antibody) in which residues from a hypervariable region ofthe recipient are replaced by residues from a hypervariable region of anon-human species (donor antibody) such as mouse, rat, rabbit ornonhuman primate having the desired specificity, affinity, and capacity.In some instances, framework region (FR) residues of the humanimmunoglobulin are replaced by corresponding non-human residues.Furthermore, humanized antibodies may comprise residues that are notfound in the recipient antibody or in the donor antibody, including, forexample non-antibody sequences such as a chemokine, growth factor,peptide, cytokine, cell surface protein, serum protein, toxin,extracellular matrix protein, clotting factor, or secreted proteinsequence. These modifications may be made to further refine antibodyperformance. Humanized antibodies include human engineered antibodies,for example, as described by U.S. Pat. No. 5,766,886, including methodsfor preparing modified antibody variable domains. A humanized antibodymay comprise substantially all of at least one, and typically two,variable domains, in which all or substantially all of the hypervariableloops correspond to those of a non-human immunoglobulin and all orsubstantially all of the FRs are those of a human immunoglobulinsequence. A humanized antibody optionally may also comprise at least aportion of an immunoglobulin constant region (Fc), typically that of ahuman immunoglobulin. For further details, see Jones et al., Nature321:522-525 (1986); Riechmann et al., Nature 332:323-329 (1988); andPresta, Curr. Op. Struct. Biol. 2:593-596 (1992). See also the followingreview articles and references cited therein: Vaswani and Hamilton, Ann.Allergy, Asthma & Immunol. 1: 105-115 (1998); Harris, Biochem. Soc.Transactions 23:1035-1038 (1995); Hurle and Gross, Curr. Op. Biotech.5:428-433 (1994).

“Hybrid antibodies” refer to immunoglobulin molecules in which pairs ofheavy and light chains from antibodies with different antigenicdeterminant regions are assembled together so that two differentepitopes or two different antigens can be recognized and bound by theresulting tetramer.

“Chimeric” antibodies (immunoglobulins) have a portion of the heavyand/or light chain identical with or homologous to correspondingsequences in antibodies derived from a particular species or belongingto a particular antibody class or subclass, while the remainder of thechain(s) is identical with or homologous to corresponding sequences inantibodies derived from another species or belonging to another antibodyclass or subclass, as well as fragments of such antibodies, so long asthey exhibit the desired biological activity (see e.g., Morrison et al.,Proc. Natl. Acad. Sci. USA 81:6851-6855 (1984)). Humanized antibodyrefers to a subset of chimeric antibodies.

“Single-chain Fv” or “scFv” antibody fragments may comprise the VH andVL domains of antibody, wherein these domains are present in a singlepolypeptide chain. Generally, the scFv polypeptide further comprises apolypeptide linker between the VH and VL domains which enables the scFvto form the desired structure for antigen binding. For a review of scFv,see e.g., Pluckthun, in The Pharmacology of Monoclonal Antibodies, vol.113, Rosenburg and Moore eds., Springer-Verlag, New York, pp. 269-315(1994).

An “antigen” refers to a predetermined antigen to which an antibody canselectively bind. The target antigen may be polypeptide, carbohydrate,nucleic acid, lipid, hapten or other naturally occurring or syntheticcompound. Preferably, the target antigen is a polypeptide.

“Epitope” or “antigenic determinant”, used interchangeably herein, referto that portion of an antigen capable of being recognized andspecifically bound by a particular antibody. When the antigen is apolypeptide, epitopes can be formed both from contiguous amino acids andnoncontiguous amino acids juxtaposed by tertiary folding of a protein.Epitopes formed from contiguous amino acids are typically retained uponprotein denaturing, whereas epitopes formed by tertiary folding aretypically lost upon protein denaturing. An epitope typically includes atleast 3, and more usually, at least 5 or 8-10 amino acids in a uniquespatial conformation. Antibodies may bind to the same or a differentepitope on an antigen. Antibodies may be characterized in differentepitope bins. Whether an antibody binds to the same or different epitopeas another antibody (e.g., a reference antibody or benchmark antibody)may be determined by competition between antibodies in assays (e.g.,competitive binding assays).

Competition between antibodies may be determined by an assay in whichthe immunoglobulin under test inhibits specific binding of a referenceantibody to a common antigen. Numerous types of competitive bindingassays are known, for example: solid phase direct or indirectradioimmunoassay (RIA), solid phase direct or indirect enzymeimmunoassay or enzyme-linked immunosorbent assay (EIA or ELISA),sandwich competition assay including an ELISA assay (see Stahli et al.,Methods in Enzymology 9:242-253 (1983)); solid phase directbiotin-avidin EIA (see Kirkland et al., J. Immunol. 137:3614-3619(1986)); solid phase direct labeled assay, solid phase direct labeledsandwich assay (see Harlow and Lane, “Antibodies, A Laboratory Manual,”Cold Spring Harbor Press (1988)); solid phase direct label RIA using1-125 label (see Morel et al., Molec. Immunol. 25(1):7-15 (1988)); solidphase direct biotin-avidin EIA (Cheung et al., Virology 176:546-552(1990)); and direct labeled RIA (Moldenhauer et al., Scand. J. Immunol.,32:77-82 (1990)). Competition binding assays may be performed usingSurface Plasmon Resonance (SPR), for example, with a Biacore® instrumentfor kinetic analysis of binding interactions. In such an assay, ahumanized antibody comprising an ultralong CDR3 of unknown epitopespecificity may be evaluated for its ability to compete for bindingagainst a comparator antibody (e.g., a BA1 or BA2 antibody as describedherein). An assay may involve the use of purified antigen bound to asolid surface or cells bearing either of these, an unlabeled testimmunoglobulin and a labeled reference immunoglobulin. Competitiveinhibition may be measured by determining the amount of label bound tothe solid surface or cells in the presence of the test immunoglobulin.Usually the test immunoglobulin is present in excess. An assay(competing antibodies) may include antibodies binding to the sameepitope as the reference antibody and antibodies binding to an adjacentepitope sufficiently proximal to the epitope bound by the referenceantibody for steric hindrance to occur. Usually, when a competingantibody is present in excess, it will inhibit specific binding of areference antibody to a common antigen by at least 50%, or at leastabout 70%, or at least about 80%, or least about 90%, or at least about95%, or at least about 99% or about 100% for a competitor antibody.

That an antibody “selectively binds” or “specifically binds” means thatthe antibody reacts or associates more frequently, more rapidly, withgreater duration, with greater affinity, or with some combination of theabove to an antigen or an epitope than with alternative substances,including unrelated proteins. “Selectively binds” or “specificallybinds” may mean, for example, that an antibody binds to a protein with aK_(D) of at least about 0.1 mM, or at least about 1 μM or at least about0.1 μM or better, or at least about 0.01 μM or better. Because of thesequence identity between homologous proteins in different species,specific binding can include an antibody that recognizes a given antigenin more than one species.

“Non-specific binding” and “background binding” when used in referenceto the interaction of an antibody and a protein or peptide refer to aninteraction that is not dependent on the presence of a particularstructure (e.g., the antibody is binding to proteins in general ratherthat a particular structure such as an epitope).

“Diabodies” refer to small antibody fragments with two antigen-bindingsites, which fragments comprise a heavy-chain variable domain (VH)connected to a light-chain variable domain (VL) in the same polypeptidechain (VH-VL). By using a linker that is too short to allow pairingbetween the two domains on the same chain, the domains are forced topair with the complementary domains of another chain and create twoantigen-binding sites. Diabodies are described more fully in, forexample, EP 404,097; WO 93/11161; and Hollinger et. al., Proc. Natl.Acad. Sci. USA, 90:6444-6448 (1993).

A “human antibody” refers to one which possesses an amino acid sequencewhich corresponds to that of an antibody produced by a human and/or hasbeen made using any of the techniques for making human antibodies asdisclosed herein. This definition of a human antibody specificallyexcludes a humanized antibody comprising non-human antigen-bindingresidues.

An “affinity matured” antibody refers to one with one or morealterations in one or more CDRs thereof which result in an improvementin the affinity of the antibody for antigen, compared to a parentantibody which does not possess those alteration(s). Preferred affinitymatured antibodies will have nanomolar or even picomolar affinities forthe target antigen. Affinity matured antibodies are produced byprocedures known in the art. Marks et al., Bio/Technology 10:779-783(1992) describes affinity maturation by VH and VL domain shuffling.Random mutagenesis of CDR and/or framework residues is described by:Barbas et al., Proc Nat. Acad. Sci. USA 91:3809-3813 (1994); Schier etal., Gene 169:147-155 (1995); Yelton et al., J. Immunol. 155:1994-2004(1995); Jackson et al., J. Immunol. 154(7):3310-9 (1995); and Hawkins etal., J. Mol. Biol. 226:889-896 (1992).

Antibody “effector functions” refer to those biological activitiesattributable to the Fc region (a native sequence Fc region or amino acidsequence variant Fc region) of an antibody, and vary with the antibodyisotype. Examples of antibody effector functions include: Clq bindingand complement dependent cytotoxicity; Fc receptor binding;antibody-dependent cell-mediated cytotoxicity (ADCC); phagocytosis; downregulation of cell surface receptors (e.g. B cell receptor); and B cellactivation.

“Antibody-dependent cell-mediated cytotoxicity” or “ADCC” refers to aform of cytotoxicity in which secreted Ig bound onto Fc receptors (FcRs)present on certain cytotoxic cells (e.g., Natural Killer (NK) cells,neutrophils, and macrophages) enable these cytotoxic effector cells tobind specifically to an antigen-bearing target cell and subsequentlykill the target cell with cytotoxins. The antibodies “arm” the cytotoxiccells and are absolutely required for such killing. The primary cellsfor mediating ADCC, NK cells, express FcγRIII only, whereas monocytesexpress FcγRI, FcγRII and FcγRIII. FcR expression on hematopoietic cellsis summarized in Table 3 on page 464 of Ravetch and Kinet, Annu. Rev.Immunol 9:457-92 (1991). To assess ADCC activity of a molecule ofinterest, an in vitro ADCC assay, may be performed. Useful effectorcells for such assays include peripheral blood mononuclear cells (PBMC)and Natural Killer (NK) cells. Alternatively, or additionally, ADCCactivity of the molecule of interest may be assessed in vivo, e.g., in aanimal model such as that disclosed in Clynes et al. Proc. Natl. Acad.Sci. USA 95:652-656 (1998).

“Human effector cells” are leukocytes which express one or more FcRs andperform effector functions. Preferably, the cells express at leastFcγRIII and perform ADCC effector function. Examples of human leukocyteswhich mediate ADCC include peripheral blood mononuclear cells (PBMC),natural killer (NK) cells, monocytes, cytotoxic T cells and neutrophils;with PBMCs and NK cells being preferred. The effector cells may beisolated from a native source, e.g., from blood.

“Fc receptor” or “FcR” describes a receptor that binds to the Fc regionof an antibody. The preferred FcR is a native sequence human FcR.Moreover, a preferred FcR is one which binds an IgG antibody (a gammareceptor) and includes receptors of the FcγRI, FcγRII, and FcγRIIIsubclasses, including allelic variants and alternatively spliced formsof these receptors. FcγRII receptors include FcγRIIA (an “activatingreceptor”) and FcγRIIB (an “inhibiting receptor”), which have similaramino acid sequences that differ primarily in the cytoplasmic domainsthereof. Activating receptor FcγRIIA contains an immunoreceptortyrosine-based activation motif (ITAM) in its cytoplasmic domain.Inhibiting receptor FcγRIIB contains an immunoreceptor tyrosine-basedinhibition motif (ITIM) in its cytoplasmic domain. (see review M. inDaeron, Annu. Rev. Immunol. 15:203-234 (1997)). FcRs are reviewed inRavetch and Kinet, Annu. Rev. Immunol 9:457-92 (1991); Capel et al.,Immunomethods 4:25-34 (1994); and de Haas et al., J. Lab. Clin. Med.126:330-41 (1995). Other FcRs, including those to be identified in thefuture, are encompassed by the term “FcR” herein. The term also includesthe neonatal receptor, FcRn, which is responsible for the transfer ofmaternal IgGs to the fetus (Guyer et al., J. Immunol. 117:587 (1976) andKim et al., J. Immunol. 24:249 (1994)) and regulates homeostasis ofimmunoglobulins. For example, antibody variants with improved ordiminished binding to FcRs have been described (see, e.g., Shields etal. J. Biol. Chem. 9(2): 6591-6604 (2001)).

Methods of measuring binding to FcRn are known (see, e.g., Ghetie 1997,Hinton 2004). Binding to human FcRn in vivo and serum half life of humanFcRn high affinity binding polypeptides can be assayed, e.g., intransgenic mice or transfected human cell lines expressing human FcRn,or in primates administered with the Fc variant polypeptides.

“Complement dependent cytotoxicity” or “CDC” refers to the lysis of atarget cell in the presence of complement. Activation of the classicalcomplement pathway is initiated by the binding of the first component ofthe complement system (Clq) to antibodies (of the appropriate subclass)which are bound to their cognate antigen. To assess complementactivation, a CDC assay, for example, as described in Gazzano-Santoro etal., J. Immunol. Methods 202:163 (1996), may be performed.

Polypeptide variants with altered Fc region amino acid sequences andincreased or decreased Clq binding capability have been described (e.g.,see, also, Idusogie et al. J. Immunol. 164: 4178-4184 (2000)).

“Fc region-comprising polypeptide” refers to a polypeptide, such as anantibody or immunoadhesin (see definitions below), which comprises an Fcregion. The C-terminal lysine (residue 447 according to the EU numberingsystem) of the Fc region may be removed, for example, duringpurification of the polypeptide or by recombinant engineering thenucleic acid encoding the polypeptide.

“Blocking” antibody or an “antagonist” antibody refers to one whichinhibits or reduces biological activity of the antigen it binds.Preferred blocking antibodies or antagonist antibodies substantially orcompletely inhibit the biological activity of the antigen.

“Agonist” antibody refers to an antibody which mimics (e.g., partiallyor fully) at least one of the functional activities of a polypeptide ofinterest.

“Acceptor human framework” refers to a framework comprising the aminoacid sequence of a VL or VH framework derived from a humanimmunoglobulin framework, or from a human consensus framework. Anacceptor human framework “derived from” a human immunoglobulin frameworkor human consensus framework may comprise the same amino acid sequencethereof, or may contain pre-existing amino acid sequence changes. Wherepre-existing amino acid changes are present, preferably no more than 5and preferably 4 or less, or 3 or less, pre-existing amino acid changesare present.

A “human consensus framework” refers to a framework which represents themost commonly occurring amino acid residues in a selection of humanimmunoglobulin VL or VH framework sequences. Generally, the selection ofhuman immunoglobulin VL or VH sequences is from a subgroup of variabledomain sequences. Generally, the subgroup of sequences is a subgroup asin Kabat et al., Sequences of Proteins of Immunological Interest, FifthEdition, NIH Publication 91-3242, Bethesda Md. (1991), vols. 1-3. In oneembodiment, for the VL, the subgroup is subgroup kappa I as in Kabat etal., supra. In one embodiment, for the VH, the subgroup is subgroup IIIas in Kabat et al., supra.

“Disorder” or “disease” refers to any condition that would benefit fromtreatment with a substance/molecule (e.g., a humanized antibodycomprising an ultralong CDR3 as disclosed herein) or method disclosedherein. This includes chronic and acute disorders or diseases includingthose pathological conditions which predispose the mammal to thedisorder in question.

“Treatment” refers to clinical intervention in an attempt to alter thenatural course of the individual or cell being treated, and can beperformed either for prophylaxis or during the course of clinicalpathology. Desirable effects of treatment include preventing occurrenceor recurrence of disease, alleviation of symptoms, diminishment of anydirect or indirect pathological consequences of the disease, preventingmetastasis, decreasing the rate of disease progression, amelioration orpalliation of the disease state, and remission or improved prognosis. Insome embodiments, antibodies disclosed herein are used to delaydevelopment of a disease or disorder.

“Individual” (e.g., a “subject”) refers to a vertebrate, preferably amammal, more preferably a human. Mammals include, but are not limitedto, farm animals (such as cows), sport animals, pets (such as cats, dogsand horses), primates, mice and rats.

“Mammal” for purposes of treatment refers to any animal classified as amammal, including humans, rodents (e.g., mice and rats), and monkeys;domestic and farm animals; and zoo, sports, laboratory, or pet animals,such as dogs, cats, cattle, horses, sheep, pigs, goats, rabbits, etc. Insome embodiments, the mammal is selected from a human, rodent, ormonkey.

“Pharmaceutically acceptable” refers to approved or approvable by aregulatory agency of the Federal or a state government or listed in theU.S. Pharmacopeia or other generally recognized pharmacopeia for use inanimals, including humans.

“Pharmaceutically acceptable salt” refers to a salt of a compound thatis pharmaceutically acceptable and that possesses the desiredpharmacological activity of the parent compound.

“Pharmaceutically acceptable excipient, carrier or adjuvant” refers toan excipient, carrier or adjuvant that can be administered to a subject,together with at least one antibody of the present disclosure, and whichdoes not destroy the pharmacological activity thereof and is nontoxicwhen administered in doses sufficient to deliver a therapeutic amount ofthe compound.

“Pharmaceutically acceptable vehicle” refers to a diluent, adjuvant,excipient, or carrier with which at least one antibody of the presentdisclosure is administered.

“Providing a prognosis”, “prognostic information”, or “predictiveinformation” refer to providing information, including for example thepresence of cancer cells in a subject's tumor, regarding the impact ofthe presence of cancer (e.g., as determined by the diagnostic methods ofthe present disclosure) on a subject's future health (e.g., expectedmorbidity or mortality, the likelihood of getting cancer, and the riskof metastasis).

Terms such as “treating” or “treatment” or “to treat” or “alleviating”or “to alleviate” refer to both 1) therapeutic measures that cure, slowdown, lessen symptoms of, and/or halt progression of a diagnosedpathologic condition or disorder and 2) prophylactic or preventativemeasures that prevent and/or slow the development of a targetedpathologic condition or disorder. Thus those in need of treatmentinclude those already with the disorder; those prone to have thedisorder; and those in whom the disorder is to be prevented.

“Providing a diagnosis” or “diagnostic information” refers to anyinformation, including for example the presence of cancer cells, that isuseful in determining whether a patient has a disease or conditionand/or in classifying the disease or condition into a phenotypiccategory or any category having significance with regards to theprognosis of or likely response to treatment (either treatment ingeneral or any particular treatment) of the disease or condition.Similarly, diagnosis refers to providing any type of diagnosticinformation, including, but not limited to, whether a subject is likelyto have a condition (such as a tumor), whether a subject's tumorcomprises cancer stem cells, information related to the nature orclassification of a tumor as for example a high risk tumor or a low risktumor, information related to prognosis and/or information useful inselecting an appropriate treatment. Selection of treatment can includethe choice of a particular chemotherapeutic agent or other treatmentmodality such as surgery or radiation or a choice about whether towithhold or deliver therapy.

A “human consensus framework” refers to a framework which represents themost commonly occurring amino acid residues in a selection of humanimmunoglobulin VL or VH framework sequences. Generally, the selection ofhuman immunoglobulin VL or VH sequences is from a subgroup of variabledomain sequences. Generally, the subgroup of sequences is a subgroup asin Kabat et al., Sequences of Proteins of Immunological Interest, FifthEdition, NIH Publication 91-3242, Bethesda Md. (1991), vols. 1-3. In oneembodiment, for the VL, the subgroup is subgroup kappa I as in Kabat etal., supra. In one embodiment, for the VH, the subgroup is subgroup IIIas in Kabat et al., supra.

An “acceptor human framework” for the purposes herein refers to aframework comprising the amino acid sequence of a light chain variabledomain (VL) framework or a heavy chain variable domain (VH) frameworkderived from a human immunoglobulin framework or a human consensusframework, as defined below. An acceptor human framework “derived from”a human immunoglobulin framework or a human consensus framework maycomprise the same amino acid sequence thereof, or it may contain aminoacid sequence changes. In some embodiments, the number of amino acidchanges are 10 or less, 9 or less, 8 or less, 7 or less, 6 or less, 5 orless, 4 or less, 3 or less, or 2 or less. In some embodiments, the VLacceptor human framework is identical in sequence to the VL humanimmunoglobulin framework sequence or human consensus framework sequence.

“Antigen-binding site” refers to the interface formed by one or morecomplementary determining regions. An antibody molecule has two antigencombining sites, each containing portions of a heavy chain variableregion and portions of a light chain variable region. The antigencombining sites can contain other portions of the variable regiondomains in addition to the CDRs.

An “antibody light chain” or an “antibody heavy chain” refers to apolypeptide comprising the VL or VH, respectively. The VL is encoded bythe minigenes V (variable) and J (junctional), and the VH by minigenesV, D (diversity), and J. Each of VL or VH includes the CDRs as well asthe framework regions. In this application, antibody light chains and/orantibody heavy chains may, from time to time, be collectively referredto as “antibody chains.” These terms encompass antibody chainscontaining mutations that do not disrupt the basic structure of VL orVH, as one skilled in the art will readily recognize.

“Native antibodies” refer to naturally occurring immunoglobulinmolecules with varying structures. For example, native IgG antibodiesare heterotetrameric glycoproteins of about 150,000 daltons, composed oftwo identical light chains and two identical heavy chains that aredisulfide bonded. From N- to C-terminus, each heavy chain has a variableregion (V H), also called a variable heavy domain or a heavy chainvariable domain, followed by three constant domains (CH1, CH2, and CH3).Similarly, from N- to C-terminus, each light chain has a variable region(V L), also called a variable light domain or a light chain variabledomain, followed by a constant light (CL) domain. The light chain of anantibody may be assigned to one of two types, called kappa (K) andlambda (K), based on the amino acid sequence of its constant domain.

“Combinatorial library” refers to collections of compounds formed byreacting different combinations of interchangeable chemical “buildingblocks” to produce a collection of compounds based on permutations ofthe building blocks. For an antibody combinatorial library, the buildingblocks are the component V, D and J regions (or modified forms thereof)from which antibodies are formed. For purposes herein, the terms“library” or “collection” are used interchangeably.

A “combinatorial antibody library” refers to a collection of antibodies(or portions thereof, such as Fabs), where the antibodies are encoded bynucleic acid molecules produced by the combination of V, D and J genesegments, particularly human V, D and J germline segments. Thecombinatorial libraries herein typically contain at least 50 differentantibody (or antibody portions or fragment) members, typically at orabout 50, 100, 500, 103, 1×103, 2×103, 3×103, 4×103, 5×103, 6×103,7×103, 8×103, 9×103, 1×104, 2×104, 3×104, 4×104, 5×104, 6×104, 7×104,8×104, 9×104, 1×105, 2×105, 3×105, 4×105, 5×105, 6×105, 7×105, 8×105,9×105, 106, 107, 108, 109, 1010, or more different members. Theresulting libraries or collections of antibodies or portions thereof,can be screened for binding to a target protein or modulation of afunctional activity.

A “human combinatorial antibody library” refers to a collection ofantibodies or portions thereof, whereby each member contains a VL and VHchains or a sufficient portion thereof to form an antigen binding siteencoded by nucleic acid containing human germline segments produced asdescribed herein.

A “variable germline segment” refers to V, D and J groups, subgroups,genes or alleles thereof. Gene segment sequences are accessible fromknown database (e.g., National Center for Biotechnology Information(NCBI), the international ImMunoGeneTics information System® (IMGT), theKabat database and the Tomlinson's VBase database (Lefranc (2003)Nucleic Acids Res., 31:307-310; Martin et al., Bioinformatics Tools forAntibody Engineering in Handbook of Therapeutic Antibodies, Wiley-VCH(2007), pp. 104-107). Tables 3-5 list exemplary human variable germlinesegments. Sequences of exemplary VH, DH, JH, Vκ, Jκ, Vλ and or Jλ,germline segments are set forth in SEQ ID NOS: 10-451 and 868. Forpurposes herein, a germline segment includes modified sequences thereof,that are modified in accord with the rules of sequence compilationprovided herein to permit practice of the method. For example, germlinegene segments include those that contain one amino acid deletion orinsertion at the 5′ or 3′ end compared to any of the sequences ofnucleotides set forth in SEQ ID NOS:10-451, 868.

“Compilation,” “compile,” “combine,” “combination,” “rearrange,”“rearrangement,” or other similar terms or grammatical variationsthereof refers to the process by which germline segments are ordered orassembled into nucleic acid sequences representing genes. For example,variable heavy chain germline segments are assembled such that the VHsegment is 5′ to the DH segment which is 5′ to the JH segment, therebyresulting in a nucleic acid sequence encoding a VH chain. Variable lightchain germline segments are assembled such that the VL segment is 5′ tothe JL segment, thereby resulting in a nucleic acid sequence encoding aVL chain. A constant gene segment or segments also can be assembled ontothe 3′ end of a nucleic acid encoding a VH or VL chain.

“Linked,” or “linkage” or other grammatical variations thereof withreference to germline segments refers to the joining of germlinesegments. Linkage can be direct or indirect. Germline segments can belinked directly without additional nucleotides between segments, oradditional nucleotides can be added to render the entire segmentin-frame, or nucleotides can be deleted to render the resulting segmentin-frame. It is understood that the choice of linker nucleotides is madesuch that the resulting nucleic acid molecule is in-frame and encodes afunctional and productive antibody.

“In-frame” or “linked in-frame” with reference to linkage of humangermline segments means that there are insertions and/or deletions inthe nucleotide germline segments at the joined junctions to render theresulting nucleic acid molecule in-frame with the 5′ start codon (ATG),thereby producing a “productive” or functional full-length polypeptide.The choice of nucleotides inserted or deleted from germline segments,particularly at joints joining various VD, DJ and VJ segments, is inaccord with the rules provided in the method herein for V(D)J jointgeneration. For example, germline segments are assembled such that theVH segment is 5′ to the DH segment which is 5′ to the JH segment. At thejunction joining the VH and the DH and at the junction joining the DHand JH segments, nucleotides can be inserted or deleted from theindividual VH, DH or JH segments, such that the resulting nucleic acidmolecule containing the joined VDJ segments are in-frame with the 5′start codon (ATG).

A portion of an antibody includes sufficient amino acids to form anantigen binding site.

A “reading frame” refers to a contiguous and non-overlapping set ofthree-nucleotide codons in DNA or RNA. Because three codons encode oneamino acid, there exist three possible reading frames for givennucleotide sequence, reading frames 1, 2 or 3. For example, the sequenceACTGGTCA will be ACT GGT CA for reading frame 1, A CTG GTC A for readingframe 2 and AC TGG TCA for reading frame 3. Generally for practice ofthe method described herein, nucleic acid sequences are combined so thatthe V sequence has reading frame 1.

A “stop codon” refers to a three-nucleotide sequence that signals a haltin protein synthesis during translation, or any sequence encoding thatsequence (e.g. a DNA sequence encoding an RNA stop codon sequence),including the amber stop codon (UAG or TAG)), the ochre stop codon (UAAor TAA)) and the opal stop codon (UGA or TGA)). It is not necessary thatthe stop codon signal termination of translation in every cell or inevery organism. For example, in suppressor strain host cells, such asamber suppressor strains and partial amber suppressor strains,translation proceeds through one or more stop codon (e.g. the amber stopcodon for an amber suppressor strain), at least some of the time.

A “variable heavy” (VH) chain or a “variable light” (VL) chain (alsotermed VH domain or VL domain) refers to the polypeptide chains thatmake up the variable domain of an antibody. For purposes herein, heavychain germline segments are designated as VH, DH and JH, and compilationthereof results in a nucleic acid encoding a VH chain. Light chaingermline segments are designated as VL or JL, and include kappa andlambda light chains (Vκ and Jκ; Vλ and Jλ) and compilation thereofresults in a nucleic acid encoding a VL chain. It is understood that alight chain is either a kappa or lambda light chain, but does notinclude a kappa/lambda combination by virtue of compilation of a Vκ andJλ.

A “degenerate codon” refers to three-nucleotide codon that specifies thesame amino acid as a codon in a parent nucleotide sequence. One of skillin the art is familiar with degeneracy of the genetic code and canidentify degenerate codons.

“Diversity” with respect to members in a collection refers to the numberof unique members in a collection. Hence, diversity refers to the numberof different amino acid sequences or nucleic acid sequences,respectively, among the analogous polypeptide members of thatcollection. For example, a collection of polynucleotides having adiversity of 104 contains 104 different nucleic acid sequences among theanalogous polynucleotide members. In one example, the providedcollections of polynucleotides and/or polypeptides have diversities ofat least at or about 102, 103, 104, 105, 106, 107, 108, 109, 1010 ormore.

“Sequence diversity” refers to a representation of nucleic acid sequencesimilarity and is determined using sequence alignments, diversityscores, and/or sequence clustering. Any two sequences can be aligned bylaying the sequences side-by-side and analyzing differences withinnucleotides at every position along the length of the sequences.Sequence alignment can be assessed in silico using Basic Local AlignmentSearch Tool (BLAST), an NCBI tool for comparing nucleic acid and/orprotein sequences. The use of BLAST for sequence alignment is well knownto one of skill in the art. The Blast search algorithm compares twosequences and calculates the statistical significance of each match (aBlast score). Sequences that are most similar to each other will have ahigh Blast score, whereas sequences that are most varied will have a lowBlast score.

A “polypeptide domain” refers to a part of a polypeptide (a sequence ofthree or more, generally 5 or 7 or more amino acids) that is astructurally and/or functionally distinguishable or definable. Exemplaryof a polypeptide domain is a part of the polypeptide that can form anindependently folded structure within a polypeptide made up of one ormore structural motifs (e.g. combinations of alpha helices and/or betastrands connected by loop regions) and/or that is recognized by aparticular functional activity, such as enzymatic activity or antigenbinding. A polypeptide can have one, typically more than one, distinctdomains. For example, the polypeptide can have one or more structuraldomains and one or more functional domains. A single polypeptide domaincan be distinguished based on structure and function. A domain canencompass a contiguous linear sequence of amino acids. Alternatively, adomain can encompass a plurality of non-contiguous amino acid portions,which are non-contiguous along the linear sequence of amino acids of thepolypeptide. Typically, a polypeptide contains a plurality of domains.For example, each heavy chain and each light chain of an antibodymolecule contains a plurality of immunoglobulin (Ig) domains, each about110 amino acids in length.

An “Ig domain” refers to a domain, recognized as such by those in theart, that is distinguished by a structure, called the Immunoglobulin(Ig) fold, which contains two beta-pleated sheets, each containinganti-parallel beta strands of amino acids connected by loops. The twobeta sheets in the Ig fold are sandwiched together by hydrophobicinteractions and a conserved intra-chain disulfide bond. Individualimmunoglobulin domains within an antibody chain further can bedistinguished based on function. For example, a light chain contains onevariable region domain (VL) and one constant region domain (CL), while aheavy chain contains one variable region domain (VH) and three or fourconstant region domains (CH). Each VL, CL, VH, and CH domain is anexample of an immunoglobulin domain.

A “variable domain” with reference to an antibody refers to a specificIg domain of an antibody heavy or light chain that contains a sequenceof amino acids that varies among different antibodies. Each light chainand each heavy chain has one variable region domain (VL, and, VH). Thevariable domains provide antigen specificity, and thus are responsiblefor antigen recognition. Each variable region contains CDRs that arepart of the antigen binding site domain and framework regions (FRs).

A “constant region domain” refers to a domain in an antibody heavy orlight chain that contains a sequence of amino acids that iscomparatively more conserved among antibodies than the variable regiondomain. Each light chain has a single light chain constant region (CL)domain and each heavy chain contains one or more heavy chain constantregion (CH) domains, which include, CH1, CH2, CH3 and CH4. Full-lengthIgA, IgD and IgG isotypes contain CH1, CH2 CH3 and a hinge region, whileIgE and IgM contain CH1, CH2 CH3 and CH4. CH1 and CL domains extend theFab arm of the antibody molecule, thus contributing to the interactionwith antigen and rotation of the antibody arms. Antibody constantregions can serve effector functions, such as, but not limited to,clearance of antigens, pathogens and toxins to which the antibodyspecifically binds, e.g. through interactions with various cells,biomolecules and tissues.

An “antibody or portion thereof that is sufficient to form an antigenbinding site” means that the antibody or portion thereof contains atleast 1 or 2, typically 3, 4, 5 or all 6 CDRs of the VH and VLsufficient to retain at least a portion of the binding specificity ofthe corresponding full-length antibody containing all 6 CDRs. Generally,a sufficient antigen binding site at least requires CDR3 of the heavychain (CDRH3). It typically further requires the CDR3 of the light chain(CDRL3). As described herein, one of skill in the art knows and canidentify the CDRs based on Kabat or Chothia numbering (see, e.g., Kabat,E. A. et al. (1991) Sequences of Proteins of Immunological Interest,Fifth Edition, U.S. Department of Health and Human Services, NIHPublication No. 91-3242, and Chothia, C. et al. (1987) J. Mol. Biol.196:901-917). For example, based on Kabat numbering, CDR-LI correspondsto residues L24-L34; CDR-L2 corresponds to residues L50-L56; CDR-L3corresponds to residues L89-L97; CDR-H1 corresponds to residues H31-H35,35a or 35b depending on the length; CDR-H2 corresponds to residuesH50-H65; and CDR-H3 corresponds to residues H95-H102.

A “peptide mimetic” refers to a peptide that mimics the activity of apolypeptide. For example, an erythropoietin (EPO) peptide mimetic is apeptide that mimics the activity of Epo, such as for binding andactivation of the EPO receptor.

An “address” refers to a unique identifier for each locus in acollection whereby an addressed member (e.g. an antibody) can beidentified. An addressed moiety is one that can be identified by virtueof its locus or location. Addressing can be effected by position on asurface, such as a well of a microplate. For example, an address for aprotein in a microwell plate that is F9 means that the protein islocated in row F, column 9 of the microwell plate. Addressing also canbe effected by other identifiers, such as a tag encoded with a bar codeor other symbology, a chemical tag, an electronic, such RF tag, acolor-coded tag or other such identifier.

An “array” refers to a collection of elements, such as antibodies,containing three or more members.

A “spatial array” refers to an array where members are separated oroccupy a distinct space in an array. Hence, spatial arrays are a type ofaddressable array. Examples of spatial arrays include microtiter plateswhere each well of a plate is an address in the array. Spacial arraysinclude any arrangement wherein a plurality of different molecules,e.g., polypeptides, are held, presented, positioned, situated, orsupported. Arrays can include microtiter plates, such as 48-well,96-well, 144-well, 192-well, 240-well, 288-well, 336-well, 384-well,432-well, 480-well, 576-well, 672-well, 768-well, 864-well, 960-well,1056-well, 1152-well, 1248-well, 1344-well, 1440-well, or 1536-wellplates, tubes, slides, chips, flasks, or any other suitable laboratoryapparatus. Furthermore, arrays can also include a plurality ofsub-arrays. A plurality of sub-arrays encompasses an array where morethan one arrangement is used to position the polypeptides. For example,multiple 96-well plates could constitute a plurality of sub-arrays and asingle array.

An “addressable library” or “spatially addressed library” refers to acollection of molecules such as nucleic acid molecules or proteinagents, such as antibodies, in which each member of the collection isidentifiable by virtue of its address.

An “addressable array” refers to one in which the members of the arrayare identifiable by their address, the position in a spatial array, suchas a well of a microtiter plate, or on a solid phase support, or byvirtue of an identifiable or detectable label, such as by color,fluorescence, electronic signal (i.e. RF, microwave or other frequencythat does not substantially alter the interaction of the molecules ofinterest), bar code or other symbology, chemical or other such label.Hence, in general the members of the array are located at identifiableloci on the surface of a solid phase or directly or indirectly linked toor otherwise associated with the identifiable label, such as affixed toa microsphere or other particulate support (herein referred to as beads)and suspended in solution or spread out on a surface.

“An addressable combinatorial antibody library” refers to a collectionof antibodies in which member antibodies are identifiable and allantibodies with the same identifier, such as position in a spatial arrayor on a solid support, or a chemical or RF tag, bind to the sameantigen, and generally are substantially the same in amino acidsequence. For purposes herein, reference to an “addressable arrayedcombinatorial antibody library” means that the antibody members areaddressed in an array.

“In silico” refers to research and experiments performed using acomputer. In silico methods include, but are not limited to, molecularmodeling studies, biomolecular docking experiments, and virtualrepresentations of molecular structures and/or processes, such asmolecular interactions. For purposes herein, the antibody members of alibrary can be designed using a computer program that selects componentV, D and J germline segments from among those input into the computerand joins them in-frame to output a list of nucleic acid molecules forsynthesis. Thus, the recombination of the components of the antibodiesin the collections or libraries provided herein, can be performed insilico by combining the nucleotide sequences of each building block inaccord with software that contains rules for doing so. The process couldbe performed manually without a computer, but the computer provides theconvenience of speed.

A “database” refers to a collection of data items. For purposes herein,reference to a database is typically with reference to antibodydatabases, which provide a collection of sequence and structureinformation for antibody genes and sequences. Exemplary antibodydatabases include, but are not limited to, IMGT®, the internationalImMunoGeneTics information system (imgt.cines.fr; see e.g., Lefranc etal. (2008) Briefings in Bioinformatics, 9:263-275), National Center forBiotechnology Information (NCBI), the Kabat database and the Tomlinson'sVBase database (Lefranc (2003) Nucleic Acids Res., 31:307-310; Martin etal., Bioinformatics Tools for Antibody Engineering in Handbook ofTherapeutic Antibodies, Wiley-VCH (2007), pp. 104-107). A database alsocan be created by a user to include any desired sequences. The databasecan be created such that the sequences are inputted in a desired format(e.g., in a particular reading frame; lacking stop codons; lackingsignal sequences). The database also can be created to include sequencesin addition to antibody sequences.

“Screening” refers to identification or selection of an antibody orportion thereof from a collection or library of antibodies and/orportions thereof, based on determination of the activity or property ofan antibody or portion thereof. Screening can be performed in any of avariety of ways, including, for example, by assays assessing directbinding (e.g. binding affinity) of the antibody to a target protein orby functional assays assessing modulation of an activity of a targetprotein.

“Activity towards a target protein” refers to binding specificity and/ormodulation of a functional activity of a target protein, or othermeasurements that reflects the activity of an antibody or portionthereof towards a target protein.

A “target protein” refers to candidate proteins or peptides that arespecifically recognized by an antibody or portion thereof and/or whoseactivity is modulated by an antibody or portion thereof. A targetprotein includes any peptide or protein that contains an epitope forantibody recognition. Target proteins include proteins involved in theetiology of a disease or disorder by virtue of expression or activity.Exemplary target proteins are described herein.

“Hit” refers to an antibody or portion thereof identified, recognized orselected as having an activity in a screening assay.

“Iterative” with respect to screening means that the screening isrepeated a plurality of times, such as 2, 3, 4, 5 or more times, until a“Hit” is identified whose activity is optimized or improved compared toprior iterations.

“High-throughput” refers to a large-scale method or process that permitsmanipulation of large numbers of molecules or compounds, generally tensto hundred to thousands of compounds. For example, methods ofpurification and screening can be rendered high-throughput.High-throughput methods can be performed manually. Generally, however,high-throughput methods involve automation, robotics or software.

Basic Local Alignment Search Tool (BLAST) is a search algorithmdeveloped by Altschul et al. (1990) to separately search protein or DNAdatabases, for example, based on sequence identity. For example, blastnis a program that compares a nucleotide query sequence against anucleotide sequence database (e.g. GenBank). BlastP is a program thatcompares an amino acid query sequence against a protein sequencedatabase.

A BLAST bit score is a value calculated from the number of gaps andsubstitutions associated with each aligned sequence. The higher thescore, the more significant the alignment.

A “human protein” refers to a protein encoded by a nucleic acidmolecule, such as DNA, present in the genome of a human, including allallelic variants and conservative variations thereof. A variant ormodification of a protein is a human protein if the modification isbased on the wildtype or prominent sequence of a human protein.

“Naturally occurring amino acids” refer to the 20 L-amino acids thatoccur in polypeptides. The residues are those 20 α-amino acids found innature which are incorporated into protein by the specific recognitionof the charged tRNA molecule with its cognate mRNA codon in humans.

“Non-naturally occurring amino acids” refer to amino acids that are notgenetically encoded. For example, a non-natural amino acid is an organiccompound that has a structure similar to a natural amino acid but hasbeen modified structurally to mimic the structure and reactivity of anatural amino acid. Non-naturally occurring amino acids thus include,for example, amino acids or analogs of amino acids other than the 20naturally-occurring amino acids and include, but are not limited to, theD-isostereomers of amino acids. Exemplary non-natural amino acids areknown to those of skill in the art.

“Nucleic acids” include DNA, RNA and analogs thereof, including peptidenucleic acids (PNA) and mixtures thereof. Nucleic acids can be single ordouble-stranded. When referring to probes or primers, which areoptionally labeled, such as with a detectable label, such as afluorescent or radiolabel, single-stranded molecules are contemplated.Such molecules are typically of a length such that their target isstatistically unique or of low copy number (typically less than 5,generally less than 3) for probing or priming a library. Generally aprobe or primer contains at least 14, 16 or 30 contiguous nucleotides ofsequence complementary to or identical to a gene of interest. Probes andprimers can be 10, 20, 30, 50, 100 or more nucleic acids long.

A “peptide” refers to a polypeptide that is from 2 to 40 amino acids inlength.

The amino acids which occur in the various sequences of amino acidsprovided herein are identified according to their known, three-letter orone-letter abbreviations (Table 1). The nucleotides which occur in thevarious nucleic acid fragments are designated with the standardsingle-letter designations used routinely in the art.

An “amino acid” is an organic compound containing an amino group and acarboxylic acid group. A polypeptide contains two or more amino acids.For purposes herein, amino acids include the twenty naturally-occurringamino acids, non-natural amino acids and amino acid analogs (i.e., aminoacids wherein the α-carbon has a side chain).

“Amino acid residue” refers to an amino acid formed upon chemicaldigestion (hydrolysis) of a polypeptide at its peptide linkages. Theamino acid residues described herein are presumed to be in the “L”isomeric form. Residues in the “D” isomeric form, which are sodesignated, can be substituted for any L-amino acid residue as long asthe desired functional property is retained by the polypeptide. NH2refers to the free amino group present at the amino terminus of apolypeptide. COOH refers to the free carboxy group present at thecarboxyl terminus of a polypeptide. In keeping with standard polypeptidenomenclature described in J. Biol. Chem., 243: 3552-3559 (1969), andadopted 37 C.F.R. §§1.821-1.822, abbreviations for amino acid residuesare shown below:

SYMBOL 1-Letter 3-Letter AMINO ACID Y Tyr Tyrosine G Gly Glycine F PhePhenylalanine M Met Methionine A Ala Alanine S Ser Serine I IleIsoleucine L Leu Leucine T Thr Threonine V Val Valine P Pro Proline KLys Lysine H His Histidine Q Gln Glutamine E Glu Glutamic acid Z Glx Gluand/or Gln W Trp Tryptophan R Arg Arginine D Asp Aspartic acid N AsnAsparagine B Asx Asn and/or Asp C Cys Cysteine X Xaa Unknown or other

It should be noted that all amino acid residue sequences representedherein by formulae have a left to right orientation in the conventionaldirection of amino-terminus to carboxyl-terminus. In addition, thephrase “amino acid residue” is broadly defined to include the aminoacids listed in the Table of Correspondence (Table 1) and modified andunusual amino acids, such as those referred to in 37 C.F.R.§§1.821-1.822, and incorporated herein by reference. Furthermore, itshould be noted that a dash at the beginning or end of an amino acidresidue sequence indicates a peptide bond to a further sequence of oneor more amino acid residues, to an amino-terminal group such as NH2 orto a carboxyl-terminal group such as COOH. The abbreviations for anyprotective groups, amino acids and other compounds, are, unlessindicated otherwise, in accord with their common usage, recognizedabbreviations, or the IUPAC-IUB Commission on Biochemical Nomenclature(see, (1972) Biochem. 11:1726). Each naturally occurring L-amino acid isidentified by the standard three letter code (or single letter code) orthe standard three letter code (or single letter code) with the prefix“L-”; the prefix “D-” indicates that the stereoisomeric form of theamino acid is D.

An “immunoconjugate” refers to an antibody conjugated to one or moreheterologous molecule(s), including but not limited to a cytotoxicagent. An immunoconjugate may include non-antibody sequences.

General Techniques

The present disclosure relies on routine techniques in the field ofrecombinant genetics. Basic texts disclosing the general methods of usein this present disclosure include Sambrook and Russell, MolecularCloning: A Laboratory Manual 3d ed. (2001); Kriegler, Gene Transfer andExpression: A Laboratory Manual (1990); and Ausubel et al., CurrentProtocols in Molecular Biology (1994).

For nucleic acids, sizes are given in either kilobases (Kb) or basepairs (bp). These are estimates derived from agarose or polyacrylamidegel electrophoresis, from sequenced nucleic acids, or from published DNAsequences. For proteins, sizes are given in kilo-Daltons (kD) or aminoacid residue numbers. Proteins sizes are estimated from gelelectrophoresis, from sequenced proteins, from derived amino acidsequences, or from published protein sequences.

Oligonucleotides that are not commercially available can be chemicallysynthesized according to the solid phase phosphoramidite triester methodfirst described by Beaucage and Caruthers, Tetrahedron Letters,22:1859-1862 (1981), using an automated synthesizer, as described in VanDevanter et al., Nucleic Acids Res., 12:6159-6168 (1984). Purificationof oligonucleotides is by either native polyacrylamide gelelectrophoresis or by anion-exchange chromatography as described inPearson & Reanier, J. Chrom., 255:137-149 (1983). The sequence of thecloned genes and synthetic oligonucleotides can be verified aftercloning using, e.g., the chain termination method for sequencingdouble-stranded templates of Wallace et al., Gene, 16:21-26 (1981).

The nucleic acids encoding recombinant polypeptides of the presentdisclosure may be cloned into an intermediate vector beforetransformation into prokaryotic or eukaryotic cells for replicationand/or expression. The intermediate vector may be a prokaryote vectorsuch as a plasmid or shuttle vector.

Humanized Antibodies with Ultralong CDR3 Sequences

To date, cattle are the only species where ultralong CDR3 sequences havebeen identified. However, other species, for example other ruminants,may also possess antibodies with ultralong CDR3 sequences.

Exemplary antibody variable region sequences comprising an ultralongCDR3 sequence identified in cattle include those designated as: BLV1H12(see, SEQ ID NO: 22), BLV5B8 (see, SEQ ID NO: 23), BLV5D3 (see, SEQ IDNO: 24) and BLV8C11 (see, SEQ ID NO: 25) (see, e.g., Saini, et al.(1999) Eur. J. Immunol. 29: 2420-2426; and Saini and Kaushik (2002)Scand. J. Immunol. 55: 140-148); BF4E9 (see, SEQ ID NO: 26) and BF1H1(see, SEQ ID NO: 27) (see, e.g., Saini and Kaushik (2002) Scand. J.Immunol. 55: 140-148); and F18 (see, SEQ ID NO: 28) (see, e.g., Berens,et al. (1997) Int. Immunol. 9: 189-199).

In an embodiment, bovine antibodies are identified and humanized.Multiple techniques exist to identify antibodies.

Antibodies of the present disclosure may be isolated by screeningcombinatorial libraries for antibodies with the desired activity oractivities. For example, a variety of methods are known in the art forgenerating phage display libraries and screening such libraries forantibodies possessing the desired binding characteristics. Such methodsare reviewed, e.g., in Hoogenboom et al. in Methods in Molecular Biology178:1-37 (O'Brien et al., ed., Human Press, Totowa, N.J., 2001) andfurther described, e.g., in the McCafferty et al., Nature 348:552-554;Clackson et al., Nature 352: 624-628 (1991); Marks et al., J. Mol. Biol.222: 581-597 (1992); Marks and Bradbury, in Methods in Molecular Biology248:161-175 (Lo, ed., Human Press, Totowa, N.J., 2003); Sidhu et al., J.Mol. Biol. 338(2): 299-310 (2004); Lee et al., J. Mol. Biol. 340(5):1073-1093 (2004); Fellouse, Proc. Natl. Acad. Sci. USA 101(34):12467-12472 (2004); and Lee et al., J. Immunol. Methods 284(1-2):119-132 (2004).

In certain phage display methods, repertoires of VH and VL genes areseparately cloned by polymerase chain reaction (PCR) and recombinedrandomly in phage libraries, which can then be screened forantigen-binding phage as described in Winter et al., Ann. Rev. Immunol.,12: 433-455 (1994). Phage typically display antibody fragments, eitheras single-chain Fv (scFv) fragments or as Fab fragments. Libraries fromimmunized sources provide high-affinity antibodies to the immunogenwithout the requirement of constructing hybridomas. Phage displaylibraries of bovine antibodies may be a source of bovine antibody genesequences, including ultralong CDR3 sequences.

Typically, a non-human antibody is humanized to reduce immunogenicity tohumans, while retaining the specificity and affinity of the parentalnon-human antibody. Generally, a humanized antibody comprises one ormore variable domains in which CDRs (or portions thereof) are derivedfrom a non-human antibody, and FRs (or portions thereof) are derivedfrom human antibody sequences. A humanized antibody optionally will alsocomprise at least a portion of a human constant region. In someembodiments, some FR residues in a humanized antibody are substitutedwith corresponding residues from a non-human antibody (e.g., theantibody from which the CDR residues are derived), e.g., to restore orimprove antibody specificity or affinity.

Humanized antibodies and methods of making them are reviewed, e.g., inAlmagro and Fransson, Front. Biosci. 13:1619-1633 (2008), and arefurther described, e.g., in Riechmann et al., Nature 332:323-329 (1988);Queen et al., Proc. Nat'l Acad. Sci. USA 86:10029-10033 (1989); U.S.Pat. Nos. 5,821,337, 7,527,791, 6,982,321, and U.S. Pat. No. 7,087,409;Kashmiri et al., Methods 36:25-34 (2005) (describing SDR (a-CDR)grafting); Padlan, Mol. Immunol. 28:489-498 (1991) (describing“resurfacing”); Dall'Acqua et al., Methods 36:43-60 (2005) (describing“FR shuffling”); and Osbourn et al., Methods 36:61-68 (2005); Klimka etal., Br. J. Cancer, 83:252-260 (2000) (describing the “guided selection”approach to FR shuffling); and Studnicka et al., U.S. Pat. No.5,766,886.

Human variable region framework sequences that may be used forhumanization include but are not limited to: framework sequencesselected using the “best-fit” method (see, e.g., Sims et al. J. Immunol.151:2296 (1993)); framework sequences derived from the consensussequence of human antibodies of a particular subgroup of light or heavychain variable regions (see, e.g., Carter et al. Proc. Natl. Acad. Sci.USA, 89:4285 (1992); and Presta et al. J. Immunol., 151:2623 (1993));human mature (somatically mutated) framework sequences or human germlineframework sequences (see, e.g., Almagro and Fransson, Front. Biosci.13:1619-1633 (2008)); and framework sequences derived from screening FRlibraries (see, e.g., Baca et al., Biol. Chem. 272:10678-10684 (1997)and Rosok et al., J. Biol. Chem. 271:22611-22618 (1996)).

Humanized antibodies with ultralong CDR3 sequences may also includeengineered non-antibody sequences, such as cytokines or growth factors,into the CDR3 region, such that the resultant humanized antibody iseffective, for example, in inhibiting tumor metastasis. Non-antibodysequences may include an interleukin sequence, a hormone sequence, acytokine sequence, a toxin sequence, a lymphokine sequence, a growthfactor sequence, a chemokine sequence, a toxin sequence, or combinationsthereof. Non-antibody sequences may be human, non-human, or synthetic.In some embodiments, the cytokine or growth factor may be shown to havean antiproliferative effect on at least one cell population. Suchcytokines, lymphokines, growth factors, or other hematopoietic factorsinclude M-CSF, GM-CSF, TNF, IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7,IL-8, IL-9, IL-10, IL-11, IL-12, IL-13, IL-14, IL-15, IL-16, IL-17,IL-18, IFN, TNFo1, TNF1, TNF2, G-CSF, Meg-CSF, GM-CSF, thrombopoietin,stem cell factor, and erythropoietin. Additional growth factors for usein humanized antibodies and/or pharmaceutical compositions of thepresent disclosure include: angiogenin, bone morphogenic protein-1, bonemorphogenic protein-2, bone morphogenic protein-3, bone morphogenicprotein-4, bone morphogenic protein-5, bone morphogenic protein-6, bonemorphogenic protein-7, bone morphogenic protein-8, bone morphogenicprotein-9, bone morphogenic protein-10, bone morphogenic protein-11,bone morphogenic protein-12, bone morphogenic protein-13, bonemorphogenic protein-14, bone morphogenic protein-15, bone morphogenicprotein receptor IA, bone morphogenic protein receptor IB, brain derivedneurotrophic factor, ciliary neutrophic factor, ciliary neutrophicfactor receptor, cytokine-induced neutrophil chemotactic factor 1,cytokine-induced neutrophil, chemotactic factor 2, cytokine-inducedneutrophil chemotactic factor 2, endothelial cell growth factor,endothelin 1, epidermal growth factor, epithelial-derived neutrophilattractant, fibroblast growth factor 4, fibroblast growth factor 5,fibroblast growth factor 6, fibroblast growth factor 7, fibroblastgrowth factor 8, fibroblast growth factor 8b, fibroblast growth factor8c, fibroblast growth factor 9, fibroblast growth factor 10, fibroblastgrowth factor acidic, fibroblast growth factor basic, glial cellline-derived neutrophic factor receptor-1, glial cell line-derivedneutrophic factor receptor-2, growth related protein, growth relatedprotein-1, growth related protein-2, growth related protein-3, heparinbinding epidermal growth factor, hepatocyte growth factor, hepatocytegrowth factor receptor, insulin-like growth factor I, insulin-likegrowth factor receptor, insulin-like growth factor II, insulin-likegrowth factor binding protein, keratinocyte growth factor, leukemiainhibitory factor, leukemia inhibitory factor receptor-1, nerve growthfactor nerve growth factor receptor, neurotrophin-3, neurotrophin-4,placenta growth factor, placenta growth factor 2, platelet-derivedendothelial cell growth factor, platelet derived growth factor, plateletderived growth factor A chain, platelet derived growth factor AA,platelet derived growth factor AB, platelet derived growth factor Bchain, platelet derived growth factor BB, platelet derived growth factorreceptor-1, platelet derived growth factor receptor-2, pre-B cell growthstimulating factor, stem cell factor, stem cell factor receptor,transforming growth factor-1, transforming growth factor-2, transforminggrowth factor-1, transforming growth factor-1.2, transforming growthfactor-2, transforming growth factor-3, transforming growth factor-S,latent transforming growth factor-1, transforming growth factor-1binding protein I, transforming growth factor-1 binding protein II,transforming growth factor-1 binding protein III, tumor necrosis factorreceptor type I, tumor necrosis factor receptor type II, urokinase-typeplasminogen activator receptor, vascular endothelial growth factor, andchimeric proteins and biologically or immunologically active fragmentsthereof. Exemplary non-antibody sequences include interleukin 8 (IL-8,SEQ ID NO: 475), interleukin 21 (IL-21, SEQ ID NO: 480),CXCL12/SDF-1alpha (SEQ ID NO: 479), somatostain (SEQ ID NO: 477),ProTx-II (SEQ ID NO: 481), chlorotoxin (SEQ ID NO: 478), and ziconotide(SEQ ID NO: 476).

A non-human antibody may be humanized to reduce immunogenicity tohumans, while retaining the specificity and affinity of the parentalnon-human antibody. Generally, a humanized antibody comprises one ormore variable domains in which HVRs, e.g., CDRs, (or portions thereof)are derived from a non-human antibody, and FRs (or portions thereof) arederived from human antibody sequences. A humanized antibody optionallywill also comprise at least a portion of a human constant region. Insome embodiments, some FR residues in a humanized antibody aresubstituted with corresponding residues from a non-human antibody (e.g.,the antibody from which the HVR residues are derived), e.g., to restoreor improve antibody specificity or affinity.

The humanized antibodies comprising an ultralong CDR3 as disclosedherein are preferably monoclonal. Also encompassed within the scope ofthe disclosure are Fab, Fab′, Fab′-SH and F(ab′)² fragments of thehumanized antibodies comprising an ultralong CDR3 as provided herein.These antibody fragments can be created by traditional means, such asenzymatic digestion, or may be generated by recombinant techniques. Suchantibody fragments may be chimeric or humanized. These fragments areuseful for the diagnostic and therapeutic purposes set forth below.

Monoclonal antibodies are obtained from a population of substantiallyhomogeneous antibodies, e.g., the individual antibodies comprising thepopulation are identical except for possible naturally occurringmutations that may be present in minor amounts. Thus, the modifier“monoclonal” indicates the character of the antibody as not being amixture of discrete antibodies.

The humanized antibodies comprising an ultralong CDR3 as disclosedherein can be made using a hybridoma cell-based method first describedby Kohler et al., Nature, 256:495 (1975), or may be made by recombinantDNA methods.

Hybridoma cells can be generated by fusing B cells producing a desiredantibody with an immortalized cell line, usually a myeloma cell line, sothat the resulting fusion cells will be an immortalized cell line thatsecrets a particular antibody. By the same principle, myeloma cells canbe first transfected with a nucleic acid encoding a germline antibody Vregion and can be screened for the expression of the germline V region.Those myeloma cells with highest level of proteolytic light chainexpression can be subsequently fused with B cells that produce anantibody with desired target protein specificity. The fusion cells willproduce two types of antibodies: one is a heterologous antibodycontaining an endogenous antibody chain (either heavy or light) operablyjoined to the recombinant germline V region (either heavy or light), andthe other is the same antibody that the parental B cells would secrete(e.g. both endogenous heavy and light chains). The operably joinedheterologous heavy and light chains can be isolated by conventionalmethods such as chromatography and identification can be confirmed bytarget protein binding assays, assays identifying a unique tag of thegermline polypeptide, or endopeptidase activity assays described inother sections of this disclosure. In some cases, where the heterologousantibody is the predominant type in quantity among the two types ofantibodies, such isolation may not be needed.

The hybridoma cells may be seeded and grown in a suitable culture mediumthat preferably contains one or more substances that inhibit the growthor survival of the unfused, parental myeloma cells. For example, if theparental myeloma cells lack the enzyme hypoxanthine guaninephosphoribosyl transferase (HGPRT or HPRT), the culture medium for thehybridomas typically will include hypoxanthine, aminopterin, andthymidine (HAT medium), which substances prevent the growth ofHGPRT-deficient cells.

Preferred myeloma cells are those that fuse efficiently, support stablehigh-level production of antibody by the selected antibody-producingcells, and are sensitive to a medium such as HAT medium. Among these,myeloma cell lines may be murine myeloma lines, such as those derivedfrom MOPC-21 and MPC-11 mouse tumors available from the Salk InstituteCell Distribution Center, San Diego, Calif. USA, and SP-2 or X63-Ag8-653cells available from the American Type Culture Collection, Rockville,Md. USA. Human myeloma and mouse-human heteromyeloma cell lines alsohave been described for the production of human monoclonal antibodies(Kozbor, J. Immunol., 133:3001 (1984); Brodeur et al., MonoclonalAntibody Production Techniques and Applications, pp. 51-63 (MarcelDekker, Inc., New York, 1987)).

Culture medium in which hybridoma cells are growing is assayed forproduction of humanized antibodies comprising an ultralong CDR3. Forexample, the binding specificity of monoclonal antibodies produced byhybridoma cells may be determined by immunoprecipitation or by an invitro binding assay, such as an enzyme-linked immunoadsorbent assay(ELISA).

The binding affinity of the monoclonal antibody can, for example, bedetermined by the Scatchard analysis of Munson et al., Anal. Biochem.,107:220 (1980).

After hybridoma cells are identified that produce antibodies of thedesired specificity, affinity, and/or activity, the clones may besubcloned by limiting dilution procedures and grown by standard methods(Goding, Monoclonal Antibodies: Principles and Practice, pp. 59-103(Academic Press, 1986)). Suitable culture media for this purposeinclude, for example, D-MEM or RPMI-1640 medium. In addition, thehybridoma cells may be grown in vivo as ascites tumors in an animal.

The monoclonal antibodies secreted by the subclones are suitablyseparated from the culture medium, ascites fluid, or serum byconventional immunoglobulin purification procedures such as, forexample, protein A-Sepharose, hydroxylapatite chromatography, gelelectrophoresis, dialysis, or affinity chromatography.

The humanized antibodies comprising an ultralong CDR3 as disclosedherein may be made by using combinatorial libraries to screen forsynthetic antibody clones with the desired activity or activities. Forexample, synthetic antibody clones are selected by screening phagelibraries containing phage that display various fragments of antibodyvariable regions (e.g., scFv or Fab) fused to phage coat protein. Suchphage libraries may be panned, for example, by affinity chromatographyagainst the desired antigen. Clones expressing antibody fragmentscapable of binding to the desired antigen may be adsorbed to the antigenand thus separated from the non-binding clones in the library. Thebinding clones may then be eluted from the antigen, and can be furtherenriched by additional cycles of antigen adsorption/elution. Any of thehumanized antibodies comprising an ultralong CDR3 as disclosed hereinmay be obtained by designing a suitable antigen screening procedure toselect for the phage clone of interest followed by construction of afull length antibody comprising an ultralong CDR3 clone using the VH andVL (e.g., from scFv or Fab) sequences from the phage clone of interestand suitable constant region (Fc) sequences described in Kabat et al.,Sequences of Proteins of Immunological Interest, Fifth Edition, NIHPublication 91-3242, Bethesda Md. (1991), vols. 1-3.

The antigen-binding domain of an antibody is formed from two variable(V) regions, one each from the light (VL) and heavy (VH) chains, thatboth present three hypervariable loops or complementarity-determiningregions (CDRs). Variable domains may be displayed functionally on phage,either as single-chain Fv (scFv, also referred to as single-chainantibody (SCA)) fragments, in which VH and VL are covalently linkedthrough a short, flexible peptide, or as Fab fragments, in which theyare each fused to a constant domain and interact non-covalently, asdescribed in Winter et al., Ann. Rev. Immunol., 12: 433-455 (1994). scFvor SCA encoding phage clones and Fab encoding phage clones may beseparately or collectively referred to as “Fv phage clones” or “Fvclones”.

Repertoires of VH and VL genes may be separately cloned by polymerasechain reaction (PCR) and recombined randomly in phage libraries, whichcan then be searched for antigen-binding clones as described in Winteret al., Ann. Rev. Immunol., 12: 433-455 (1994). Libraries from immunizedsources provide high-affinity antibodies to the immunogen without therequirement of constructing hybridomas. Alternatively, the naiverepertoire may be cloned to provide a single source of human antibodiesto a wide range of non-self and also self antigens without anyimmunization as described by Griffiths et al., EMBO J. 12: 725-734(1993). Finally, naive libraries can also be made synthetically bycloning the unrearranged V-gene segments from stem cells, and using PCRprimers containing random sequence to encode the highly variable CDR3regions and to accomplish rearrangement in vitro as described byHoogenboom and Winter, J. Mol. Biol., 227: 381-388 (1992).

Filamentous phage is used to display antibody fragments by fusion to theminor coat protein pill. Protein pill may include truncated forms ofpill. The antibody fragments can be displayed as single chain Fvfragments, in which VH and VL domains are connected on the samepolypeptide chain by a flexible polypeptide spacer, (e.g., as describedby Marks et al., J. Mol. Biol., 222: 581-597 (1991)), or as Fabfragments, in which one chain is fused to pill (e.g., a truncated pill)and the other is secreted into the bacterial host cell periplasm whereassembly of a Fab-coat protein structure which becomes displayed on thephage surface by displacing some of the wild type coat proteins, (e.g.,as described in Hoogenboom et al., Nucl. Acids Res., 19: 4133-4137(1991)).

Nucleic acid encoding antibody variable gene segments (including VH andVL segments) are recovered from the cells of interest and and may beamplified or copies made by recombinant DNA techniques (e.g., Kunkelmutagenesis). For example, in the case of rearranged VH and VL genelibraries, the desired DNA may be obtained by isolating genomic DNA ormRNA from lymphocytes followed by polymerase chain reaction (PCR) withprimers matching the 5′ and 3′ ends of rearranged VH and VL genes asdescribed in Orlandi et al., Proc. Natl. Acad. Sci. (USA), 86: 3833-3837(1989), thereby making diverse V gene repertoires for expression. The Vgenes may be amplified from cDNA and genomic DNA, with back primers atthe 5′ end of the exon encoding the mature V-domain and forward primersbased within the J-segment as described in Orlandi et al. (1989) and inWard et al., Nature, 341: 544-546 (1989). For amplifying from cDNA, backprimers can also be based in the leader exon as described in Jones etal., Biotechnol., 9: 88-89 (1991), and forward primers within theconstant region as described in Sastry et al., Proc. Natl. Acad. Sci.(USA), 86: 5728-5732 (1989). To enhance or maximize complementarity,degeneracy may be incorporated in the primers as described in Orlandi etal. (1989) or Sastry et al. (1989). Library diversity may be enhanced ormaximized by using PCR primers targeted to each V-gene family in orderto amplify available VH and VL arrangements present in the immune cellnucleic acid sample, for example, as described in the method of Marks etal., J. Mol. Biol., 222: 581-597 (1991) or as described in the method ofOrum et al., Nucleic Acids Res., 21: 4491-4498 (1993). For cloning ofthe amplified DNA into expression vectors, rare restriction may can beintroduced within the PCR primer as a tag at one end as described inOrlandi et al. (1989), or by further PCR amplification with a taggedprimer as described in Clackson et al., Nature, 352: 624-628 (1991).

Repertoires of synthetically rearranged V genes may be derived in vitrofrom V gene segments. Most of the human VH-gene segments have beencloned and sequenced (e.g., reported in Tomlinson et al., J. Mol. Biol.,227: 776-798 (1992)), and mapped (e.g., reported in Matsuda et al.,Nature Genet., 3: 88-94 (1993); these cloned segments (including all themajor conformations of the H1 and H2 loop) may be used to generatediverse VH gene repertoires with PCR primers encoding H3 loops ofdiverse sequence and length as described in Hoogenboom and Winter, J.Mol. Biol., 227: 381-388 (1992). VH repertoires may also be made withall the sequence diversity focused in a long H3 loop of a single lengthas described in Barbas et al., Proc. Natl. Acad. Sci. USA, 89: 4457-4461(1992). Human VK and VA. segments have been cloned and sequenced(reported in Williams and Winter, Eur. J. Immunol., 23: 1456-1461(1993)) and can be used to make synthetic light chain repertoires.Synthetic V gene repertoires, based on a range of VH and VL folds, andL3 and H3 lengths, will encode antibodies of considerable structuraldiversity. Following amplification of V-gene encoding DNAs, germlineV-gene segments can be rearranged in vitro according to the methods ofHoogenboom and Winter, J. Mol. Biol., 227: 381-388 (1992).

Repertoires of antibody fragments may be constructed by combining VH andVL gene repertoires together in several ways. Each repertoire may becreated in different vectors, and the vectors recombined in vitro, forexample, as described in Hogrefe et al., Gene, 128: 119-126 (1993), orin vivo by combinatorial infection, for example, the loxP systemdescribed in Waterhouse et al., Nucl. Acids Res., 21: 2265-2266 (1993).The in vivo recombination approach exploits the two-chain nature of Fabfragments to overcome the limit on library size imposed by E. colitransformation efficiency. Naive VH and VL repertoires are clonedseparately, one into a phagemid and the other into a phage vector. Thetwo libraries are then combined by phage infection ofphagemid-containing bacteria so that each cell contains a differentcombination and the library size is limited only by the number of cellspresent (about 10¹² clones). Both vectors contain in vivo recombinationsignals so that the VH and VL genes are recombined onto a singlereplicon and are co-packaged into phage virions. These large librariesmay provide large numbers of diverse antibodies of good affinity (K_(d)⁻¹ of about 10⁻⁸ M).

Alternatively, the repertoires may be cloned sequentially into the samevector, for example, as described in Barbas et al., Proc. Natl. Acad.Sci. USA, 88: 7978-7982 (1991), or assembled together by PCR and thencloned, for example, as described in Clackson et al., Nature, 352:624-628 (1991). PCR assembly may also be used to join VH and VL DNAswith DNA encoding a flexible peptide spacer to form single chain Fv(scFv) repertoires. In yet another technique, “in cell PCR assembly” maybe used to combine VH and VL genes within lymphocytes by PCR and thenclone repertoires of linked genes as described in Embleton et al., Nucl.Acids Res., 20: 3831-3837 (1992).

The antibodies produced by naive libraries (either natural or synthetic)can be of moderate affinity (K_(d) ⁻¹ of about 10⁶ to 10⁷M⁻¹), butaffinity maturation may also be mimicked in vitro by constructing andreselecting from secondary libraries as described in Winter et al.(1994), supra. For example, mutation can be introduced at random invitro by using error-prone polymerase (reported in Leung et al.,Technique, 1: 11-15 (1989)) in the method of Hawkins et al., J. Mol.Biol., 226: 889-896 (1992) or in the method of Gram et al., Proc. Natl.Acad. Sci. USA, 89: 3576-3580 (1992). Additionally, affinity maturationmay be performed by randomly mutating one or more CDRs, for example,using PCR with primers carrying random sequence spanning the CDR ofinterest, in selected individual Fv clones and screening for higheraffinity clones. WO 9607754 described a method for inducing mutagenesisin a complementarity determining region of an immunoglobulin light chainto create a library of light chain genes. Another effective approach isto recombine the VH or VL domains selected by phage display withrepertoires of naturally occurring V domain variants obtained fromunimmunized donors and screen for higher affinity in several rounds ofchain reshuffling as described in Marks et al., Biotechnol., 10: 779-783(1992). This technique allows the production of antibodies and antibodyfragments with affinities in the 10⁻⁹ M range.

The phage library samples are contacted with an immobilized proteinunder conditions suitable for binding of at least a portion of the phageparticles with the adsorbent. Normally, the conditions, including pH,ionic strength, temperature and the like are selected to mimicphysiological conditions. The phages bound to the solid phase are washedand then eluted by acid, e.g., as described in Barbas et al., Proc.Natl. Acad. Sci. USA, 88: 7978-7982 (1991), or by alkali, (e.g., asdescribed in Marks et al., J. Mol. Biol., 222: 581-597 (1991)), or byantigen competition, (e.g., in a procedure similar to the antigencompetition method of Clackson et al., Nature, 352: 624-628 (1991)).Phages may be enriched 20-1,000-fold in a single round of selection.Moreover, the enriched phages may be grown in bacterial culture andsubjected to further rounds of selection.

The efficiency of selection depends on many factors, including thekinetics of dissociation during washing, and whether multiple antibodyfragments on a single phage can simultaneously engage with antigen.Antibodies with fast dissociation kinetics (and weak binding affinities)may be retained by use of short washes, multivalent phage display andhigh coating density of antigen in solid phase. The high density notonly stabilizes the phage through multivalent interactions, but favorsrebinding of phage that has dissociated. The selection of antibodieswith slow dissociation kinetics (and good binding affinities) may bepromoted by use of long washes and monovalent phage display as describedin Bass et al., Proteins, 8: 309-314 (1990) and in WO 92/09690, and alow coating density of antigen as described in Marks et al.,Biotechnol., 10: 779-783 (1992).

DNA encoding the hybridoma-derived monoclonal antibodies or phagedisplay Fv clones disclosed herein is readily isolated and sequencedusing conventional procedures (e.g., by using oligonucleotide primersdesigned to specifically amplify the heavy and light chain codingregions of interest from hybridoma or phage DNA template). Onceisolated, the DNA can be placed into expression vectors, which are thentransfected into host cells such as E. coli cells, simian COS cells,Chinese hamster ovary (CHO) cells, or myeloma cells that do nototherwise produce immunoglobulin protein, to obtain the synthesis of thedesired monoclonal antibodies in the recombinant host cells. Recombinantexpression in bacteria of antibody-encoding DNA has been described byBetter et al., U.S. Pat. No. 6,204,023 (see also, e.g., Skerra et al.,Curr. Opinion in Immunol., 5: 256 (1993) and Pluckthun, Immunol. Revs,130: 151 (1992)).

DNA encoding Fv clones as disclosed herein may be combined with knownDNA sequences encoding heavy chain and/or light chain constant regions(e.g., the appropriate DNA sequences can be obtained from Kabat et al.,supra) to form clones encoding full or partial length heavy and/or lightchains. It will be appreciated that constant regions of any isotype canbe used for this purpose, including IgG, IgM, IgA, IgD, and IgE constantregions, and that such constant regions may be obtained from any humanor animal species. A Fv clone derived from the variable domain DNA ofone animal (such as human) species and then fused to constant region DNAof another animal species to form coding sequence(s) for “hybrid”, fulllength heavy chain and/or light chain is included in the definition of“chimeric” and “hybrid” antibody as used herein. In a preferred Fv cloneembodiment, aFv clone derived from human variable DNA is fused to humanconstant region DNA to form coding sequence(s) for all human, full orpartial length heavy and/or light chains.

DNA encoding a humanized antibody comprising an ultralong CDR3 derivedfrom a hybridoma disclosed herein may also be modified, for example, bysubstituting the coding sequence for human heavy- and light-chainconstant domains in place of homologous murine sequences derived fromthe hybridoma clone (e.g., as in the method of Morrison et al., Proc.Natl. Acad. Sci. USA, 81: 6851-6855 (1984)). DNA encoding a hybridoma orFv clone-derived antibody or fragment can be further modified bycovalently joining to the immunoglobulin coding sequence all or part ofthe coding sequence for a non-immunoglobulin polypeptide. In thismanner, “chimeric” or “hybrid” antibodies are prepared that have thebinding specificity of the Fv clone or hybridoma clone-derivedantibodies disclosed herein.

Antibody Genes and Proteins

The present disclosure provides antibody genes and proteins including,for example, humanized antibody genes or proteins that comprise anultralong CDR3 sequence and/or a CDR3 scaffold. The present disclosureadditionally provides VH, DH, and JH sequences useful in the preparationof ultralong CDR3 sequences. Such sequences may comprise motifs (e.g.,cysteine motifs) as described herein including those as described in themany embodiments disclosed herein. In some embodiments, the antibodiesdisclosed herein may selectively or specifically bind to an epitope of atarget protein. In some embodiments, the antibody may be an antagonist(e.g., blocking) antibody or an agonist antibody.

The variable region of the heavy and light chains are encoded bymultiple germline gene segments separated by non-coding regions, orintrons, and often are present on different chromosomes. For example,the genes for the human immunoglobulin heavy chain region containsapproximately 65 variable (VH) genes, 27 Diversity (DH) genes, and 6Joining (JH) genes. The human kappa (κ) and lambda (λ) light chains arealso each encoded by a similar number of VL and JL gene segments, but donot include any D gene segments. Exemplary VH, DH, JH and VL (Vκ or Vλ)and JL (Jκ or Jλ) germline gene segments are set forth in WO2010/054007.

During B cell differentiation germline DNA is rearranged whereby one DHand one JH gene segment of the heavy chain locus are recombined, whichis followed by the joining of one VH gene segment forming a rearrangedVDJ gene that encodes a VH chain. The rearrangement occurs only on asingle heavy chain allele by the process of allelic exclusion. Allelicexclusion is regulated by in-frame or “productive” recombination of theVDJ segments, which occurs in only about one-third of VDJ recombinationsof the variable heavy chain. When such productive recombination eventsfirst occur in a cell, this result in production of a μ heavy chain thatgets expressed on the surface of a pre-B cell and transmits a signal toshut off further heavy chain recombination, thereby preventingexpression of the allelic heavy chain locus. The surface-expressed μheavy chain also acts to activate the kappa (κ) locus for rearrangement.The lambda (λ) locus is only activated for rearrangement if the κrecombination is unproductive on both loci. The light chainrearrangement events are similar to the heavy chain, except that onlythe VL and JL segments are recombined. Before primary transcription ofeach, the corresponding constant chain gene is added. Subsequenttranscription and RNA splicing leads to mRNA that is translated into anintact light chain or heavy chain.

The variable regions of antibodies confer antigen binding andspecificity due to recombination events of individual germline V, D andJ segments, whereby the resulting recombined nucleic acid sequencesencoding the variable region domains differ among antibodies and conferantigen-specificity to a particular antibody. The variation, however, islimited to three complementarity determining regions (CDR1, CDR2, andCDR3) found within the N-terminal domain of the heavy (H) and (L) chainvariable regions. The CDRs are interspersed with regions that are moreconserved, termed “framework regions” (FR). The extent of the frameworkregion and CDRs has been precisely defined (see e.g., Kabat, E. A. etal. (1991) Sequences of Proteins of Immunological Interest, FifthEdition, U.S. Department of Health and Human Services, NIH PublicationNo. 91-3242, and Chothia, C. et al. (1987) J. Mol. Biol. 196:901-917).Each VH and VL is typically composed of three CDRs and four FRs arrangedfrom the amino terminus to carboxy terminus in the following order: FR1,CDR1, FR2, CDR2, FR3, CDR3 and FR4. Sequence variability among VL and VHdomains is generally limited to the CDRs, which are the regions thatform the antigen binding site. For example, for the heavy chain,generally, VH genes encode the N-terminal three framework regions, thefirst two complete CDRs and the first part of the third CDR), the DHgene encodes the central portion of the third CDR, and the JH geneencodes the last part of the third CDR and the fourth framework region.For the light chain, the VL genes encode the first CDR and second CDR.The third CDR (CDRL3) is formed by the joining of the VL and JL genesegments. Hence, CDRs 1 and 2 are exclusively encoded by germline V genesegment sequences. The VH and VL chain CDR3s form the center of theAg-binding site, with CDRs 1 and 2 form the outside boundaries; the FRssupport the scaffold by orienting the H and L CDRs. On average, anantigen binding site typically requires at least four of the CDRs makecontact with the antigen's epitope, with CDR3 of both the heavy andlight chain being the most variable and contributing the mostspecificity to antigen binding (see, e.g., Janis Kuby, Immunology, ThirdEdition, New York, W.H. Freeman and Company, 1998, pp. 115-118). CDRH3,which includes all of the D gene segment, is the most diverse componentof the Ab-binding site, and typically plays a critical role in definingthe specificity of the Ab. In addition to sequence variation, there isvariation in the length of the CDRs between the heavy and light chains.

The constant regions, on the other hand, are encoded by sequences thatare more conserved among antibodies. These domains confer functionalproperties to antibodies, for example, the ability to interact withcells of the immune system and serum proteins in order to causeclearance of infectious agents. Different classes of antibodies, forexample IgM, IgD, IgG, IgE and IgA, have different constant regions,allowing them to serve distinct effector functions.

These natural recombination events of V, D, and J, can provide nearly2×10⁷ different antibodies with both high affinity and specificity.Additional diversity is introduced by nucleotide insertions anddeletions in the joining segments and also by somatic hypermutation of Vregions. The result is that there are approximately 10¹⁰ antibodiespresent in an individual with differing antigen specificities.

Antibodies include bovine antibody BLVH12 (e.g., heavy chain variableregion set forth in SEQ ID NO: 482, and light chain variable region setforth in SEQ ID NO: 483); and bovine antibody BLV5B8 (e.g., heavy chainvariable region set forth in SEQ ID NO: 484, and light chain variableregion set forth in SEQ ID NO: 485)

Antibody Fragments

The present disclosure encompasses antibody fragments. In certaincircumstances there are advantages of using antibody fragments, ratherthan whole antibodies. The smaller size of the fragments allows forrapid clearance, and may lead to improved access to solid tumors.Antibody fragments include, but are not limited to, Fab, Fab′, Fab′-SH,F(ab′)2, Fv, and scFv fragments, and other fragments described below.For a review of certain antibody fragments, see Hudson et al. Nat. Med.9:129-134 (2003). For a review of scFv fragments, see, e.g., Pluckthun,in The Pharmacology of Monoclonal Antibodies, vol. 113, Rosenburg andMoore eds., (Springer-Verlag, New York), pp. 269-315 (1994); see also WO93/16185; and U.S. Pat. Nos. 5,571,894 and 5,587,458. For discussion ofFab and F(ab′)2 fragments comprising salvage receptor binding epitoperesidues and having increased in vivo half-life, see U.S. Pat. No.5,869,046.

Diabodies are antibody fragments with two antigen binding sites that maybe bivalent or bispecific. See, for example, EP 404,097; WO 1993/01161;Hudson et al., Nat. Med. 9:129-134 (2003); and Hollinger et al., Proc.Natl. Acad. Sci. USA 90: 6444-6448 (1993). Triabodies and tetrabodiesare also described in Hudson et al., Nat. Med. 9: 129134 (2003).

Single-domain antibodies are antibody fragments comprising all or aportion of the heavy chain variable domain or all or a portion of thelight chain variable domain of an antibody. In certain embodiments, asingle-domain antibody is a human single-domain antibody (Domantis,Inc., Waltham, Mass.; see, e.g., U.S. Pat. No. 6,248,516). Antibodyfragments can be made by various techniques, including but not limitedto proteolytic digestion of an intact antibody as well as production byrecombinant host cells (e.g. E. coli or phage), as described herein.

Various techniques have been developed for the production of antibodyfragments. Traditionally, these fragments were derived via proteolyticdigestion of intact antibodies (see, e.g., Morimoto et al., Journal ofBiochemical and Biophysical Methods 24:107-117 (1992); and Brennan etal., Science, 229:81 (1985)). However, these fragments can now beproduced directly by recombinant host cells. Fab, Fv and ScFv antibodyfragments can all be expressed in and secreted from E. coli, thusallowing the facile production of large amounts of these fragments (see,e.g., U.S. Pat. No. 6,204,023). Antibody fragments can be isolated fromantibody phage libraries as discussed above. Alternatively, Fab′-SHfragments can be directly recovered from E. coli and chemically coupledto form F(ab′)₂ fragments (see, e.g., Carter et al., Bio/Technology 10:163-167 (1992)). According to another approach, F(ab′)₂ fragments can beisolated directly from recombinant host cell culture. Fab and F(ab′)₂fragment with increased in vivo half-life comprising a salvage receptorbinding epitope residues (see, e.g., in U.S. Pat. No. 5,869,046). Othertechniques for the production of antibody fragments will be apparent tothe skilled practitioner. In other embodiments, the antibody of choiceis a single chain Fv fragment (scFv or single chain antibody (SCA)). SeeWO 93/16185; U.S. Pat. Nos. 5,571,894; and 5,587,458. Fv and sFv are theonly species with intact combining sites that are devoid of constantregions; thus, they are suitable for reduced nonspecific binding duringin vivo use. sFv fusion proteins may be constructed to yield fusion ofan effector protein at either the amino or the carboxy terminus of ansFv. See Antibody Engineering, ed. Borrebaeck, Supra. The antibodyfragment may also be a “linear antibody”, for example, as described inU.S. Pat. No. 5,641,870. Such linear antibody fragments may bemonospecific or bispecific.

Humanized Antibodies

The present disclosure provides humanized antibodies comprising anultralong CDR3. Humanized antibodies may include human engineeredantibodies (see, e.g., Studnicka et al. (1994) Protein Eng. 7(6)805-814; and U.S. Pat. No. 5,766,886). Various methods for humanizingnon-human antibodies are known in the art. For example, a humanizedantibody can have one or more amino acid residues introduced into itfrom a source which is human or non-human. Humanization may be performedfollowing the method of Studnicka (see, e.g., Studnicka et al. (1994)Protein Eng. 7(6) 805-814; and U.S. Pat. No. 5,766,886), including thepreparation of modified antibody variable domains. Humanization mayalternatively be performed following the method of Winter and co-workers(Jones et al. (1986) Nature 321:522-525; Riechmann et al. (1988) Nature332:323-327; Verhoeyen et al. (1988) Science 239:1534-1536), bysubstituting hypervariable region sequences for the correspondingsequences of a human antibody. Accordingly, such “humanized” or “humanengineered” antibodies are chimeric antibodies, including whereinsubstantially less than an intact human variable domain has beensubstituted by or incorporated into the corresponding sequence from anon-human species. For example, humanized antibodies may be humanantibodies in which some hypervariable region residues and possibly someFR residues are substituted by residues from analogous sites in rodentantibodies. Alternatively, humanized or human engineered antibodies maybe non-human (e.g, rodent) antibodies in which some residues aresubstituted by residues from analogous sites in human antibodies (see,e.g., Studnicka et al. (1994) Protein Eng. 7(6) 805-814; and U.S. Pat.No. 5,766,886).

The choice of human variable domains, both light and heavy, to be usedin making the humanized antibodies is important to reduce antigenicity.For example, to the so-called “best-fit” method, the sequence of thevariable domain of a rodent antibody is screened against the entirelibrary of known human variable-domain sequences. The human sequencewhich is closest to that of the rodent is then accepted as the humanframework for the humanized antibody (Sims et al. (1993) J. Immunol.151:2296; Chothia et al. (1987) J. Mol. Biol. 196:901). Another methoduses a particular framework derived from the consensus sequence of allhuman antibodies of a particular subgroup of light or heavy chains. Thesame framework may be used for several different humanized antibodies(Carter et al. (1992) Proc. Natl. Acad. Sci. USA, 89:4285; Presta et al.(1993) J. Immunol., 151:2623).

It is further important that antibodies be humanized with retention ofhigh affinity for the antigen and other favorable biological properties.To achieve this goal, according to one method, humanized antibodies areprepared by a process of analysis of the parental sequences and variousconceptual humanized products using three-dimensional models of theparental and humanized sequences. Three-dimensional immunoglobulinmodels are commonly available and are familiar to those skilled in theart. Computer programs are available which illustrate and displayprobable three-dimensional conformational structures of selectedcandidate immunoglobulin sequences. Inspection of these displays permitsanalysis of the likely role of the residues in the functioning of thecandidate immunoglobulin sequence, e.g., the analysis of residues thatinfluence the ability of the candidate immunoglobulin to bind itsantigen. In this way, FR residues can be selected and combined from therecipient and import sequences so that the desired antibodycharacteristic, such as increased affinity for the target antigen(s), isachieved. In general, the hypervariable region residues are directly andmost substantially involved in influencing antigen binding.

In some embodiments, the humanized antibodies comprising an ultralongCDR3 may be deimmunized. Methods of deimmunizing an antibody or proteinare well known in the art. The immunogenicity of therapeutic proteinssuch as antibodies is thought to result from the presence of T-cellepitopes which can bind MHC class II molecules and generate aproliferative and cytokine response in CD4+ helper T-cells. These CD4+helper cells then collaborate with B-cells to generate an antibodyresponse against the therapeutic protein. Removal of the T-cell epitopesare thought to be key steps in deimmunizing a recombinant protein.T-cell epitopes can be predicted by in silico algorithms that identifyresidues required for binding MHC. Alternatively, epitopes can beidentified directly by utilizing peripheral blood mononuclear cells frompanels of human donors and measuring their response against thetherapeutic protein when incubated with antigen presenting cells. Suchin silico and in vitro systems are well known in the art [Jones T D,Crompton L J, Carr F J, Baker M P. Methods Mol Biol. 2009; 525:405-23,Deimmunization of monoclonal antibodies; and Baker M, and Jones TD. Theidentification and removal of immunogenicity in therapeutic proteins.Curr. Opin. Drug Discovery Dev. 2007; (2007); 10(2): 219-227]. Whenpeptides are identified that bind MHC II or otherwise stimulate CD4+cell activation, the residues of the peptide can be mutated one by oneand tested for T-cell activation until a mutation is found whichdisrupts MHC II binding and T-cell activation. Such mutations, whenfound in an individual peptide, can be encoded directly in therecombinant therapeutic protein. Incubation of the whole protein withantigen presenting cells will not induce a significant CD4+ response,indicating successful deimmunization.

Bispecific Antibodies

Bispecific antibodies are monoclonal, preferably human or humanized,antibodies that have binding specificities for at least two differentantigens. For example, one of the binding specificities may be for afirst antigen and the other may be for any other antigen. Exemplarybispecific antibodies may bind to two different epitopes of the sameprotein. Bispecific antibodies may also be used to localize cytotoxicagents to cells which express a particular protein. These antibodiespossess a binding arm specific for the particular protein and an armwhich binds the cytotoxic agent (e.g., saporin, anti-interferon-α, vincaalkaloid, ricin A chain, methotrexate or radioactive isotope hapten).Bispecific antibodies may be prepared as full length antibodies orantibody fragments (e.g., F(ab′)₂ bispecific antibodies).

Methods for making bispecific antibodies are known in the art.Traditionally, the recombinant production of bispecific antibodies isbased on the co-expression of two immunoglobulin heavy chain-light chainpairs, where the two heavy chains have different specificities (Milsteinand Cuello, Nature, 305: 537 (1983)). Because of the random assortmentof immunoglobulin heavy and light chains, these hybridomas (quadromas)produce a potential mixture of 10 different antibody molecules, of whichonly one has the correct bispecific structure. The purification of thecorrect molecule, which is usually done by affinity chromatographysteps, is rather cumbersome, and the product yields are low. Similarprocedures are disclosed in WO 93/08829, and in Traunecker et al., EMBOJ., 10: 3655 (1991).

According to a different approach, antibody variable domains with thedesired binding specificities (antibody-antigen combining sites) arefused to immunoglobulin constant domain sequences. The fusion preferablyis with an immunoglobulin heavy chain constant domain, comprising atleast part of the hinge, CH2, and CH3 regions. It is preferred to havethe first heavy-chain constant region (CH1), containing the sitenecessary for light chain binding, present in at least one of thefusions. DNAs encoding the immunoglobulin heavy chain fusions and, ifdesired, the immunoglobulin light chain, are inserted into separateexpression vectors, and are co-transfected into a suitable hostorganism. This provides for flexibility in adjusting the mutualproportions of the three polypeptide fragments in embodiments whenunequal ratios of the three polypeptide chains used in the constructionprovide the optimum yields. It is, however, possible to insert thecoding sequences for two or all three polypeptide chains in oneexpression vector when the expression of at least two polypeptide chainsin equal ratios results in high yields or when the ratios are not ofparticular significance.

In a preferred embodiment of this approach, the bispecific antibodiesare composed of a hybrid immunoglobulin heavy chain with a first bindingspecificity in one arm, and a hybrid immunoglobulin heavy chain-lightchain pair (providing a second binding specificity) in the other arm.This asymmetric structure may facilitate the separation of the desiredbispecific compound from unwanted immunoglobulin chain combinations, asthe presence of an immunoglobulin light chain in only one half of thebispecific molecule provides for a facile way of separation. Thisapproach is disclosed in WO 94/04690. For further details of generatingbispecific antibodies see, for example, Suresh et al., Methods inEnzymology, 121:210 (1986).

According to another approach, the interface between a pair of antibodymolecules may can be engineered to maximize the percentage ofheterodimers which are recovered from recombinant cell culture. Thepreferred interface comprises at least a part of the C_(H3) domain of anantibody constant domain. In this method, one or more small amino acidside chains from the interface of the first antibody molecule arereplaced with larger side chains (e.g., tyrosine or tryptophan).Compensatory “cavities” of identical or similar size to the large sidechain(s) are created on the interface of the second antibody molecule byreplacing large amino acid side chains with smaller ones (e.g., alanineor threonine). This provides a mechanism for increasing the yield of theheterodimer over other unwanted end-products such as homodimers.

Bispecific antibodies include cross-linked or “heteroconjugate”antibodies. For example, one of the antibodies in the heteroconjugatemay be coupled to avidin, the other to biotin. Such antibodies have, forexample, been proposed to target immune system cells to unwanted cells(U.S. Pat. No. 4,676,980), and for treatment of HIV infection (WO91/00360, WO 92/00373, and EP 03089). Heteroconjugate antibodies may bemade using any convenient cross-linking methods. Suitable cross-linkingagents are well known in the art, and are disclosed in U.S. Pat. No.4,676,980, along with a number of cross-linking techniques.

Techniques for generating bispecific antibodies from antibody fragmentshave also been described in the literature. For example, bispecificantibodies may be prepared using chemical linkage. Brennan et al.,Science, 229: 81 (1985) describe a procedure wherein intact antibodiesare proteolytically cleaved to generate F(ab′)₂ fragments. Thesefragments are reduced in the presence of the dithiol complexing agentsodium arsenite to stabilize vicinal dithiols and prevent intermoleculardisulfide formation. The Fab′ fragments generated are then converted tothionitrobenzoate (TNB) derivatives. One of the Fab′-TNB derivatives isthen reconverted to the Fab′-thiol by reduction with mercaptoethylamineand is mixed with an equimolar amount of the other Fab′-TNB derivativeto form the bispecific antibody. The bispecific antibodies produced maybe used as agents for the selective immobilization of enzymes.

Recent progress has facilitated the direct recovery of Fab′-SH fragmentsfrom E. coli, which can be chemically coupled to form bispecificantibodies. Shalaby et al., J. Exp. Med., 175: 217-225 (1992) describethe production of a fully humanized bispecific antibody F(ab′)₂molecule. Each Fab′ fragment was separately secreted from E. coli andsubjected to directed chemical coupling in vitro to form the bispecificantibody. The bispecific antibody thus formed was able to bind to cellsoverexpressing the HER2 receptor and normal human T cells, as well astrigger the lytic activity of human cytotoxic lymphocytes against humanbreast tumor targets.

Various techniques for making and isolating bispecific antibodyfragments directly from recombinant cell culture have also beendescribed. For example, bispecific antibodies have been produced usingleucine zippers. See, e.g., Kostelny et al., J. Immunol.,148(5):1547-1553 (1992). The leucine zipper peptides from the Fos andJun proteins were linked to the Fab′ portions of two differentantibodies by gene fusion. The antibody homodimers were reduced at thehinge region to form monomers and then re-oxidized to form the antibodyheterodimers. This method can also be utilized for the production ofantibody homodimers. The “diabody” technology described by Hollinger etal., Proc. Natl. Acad. Sci. USA, 90:6444-6448 (1993) has provided analternative mechanism for making bispecific antibody fragments. Thefragments comprise a heavy-chain variable domain (VH) connected to alight-chain variable domain (VL) by a linker which is too short to allowpairing between the two domains on the same chain. Accordingly, the VHand VL domains of one fragment are forced to pair with the complementaryVL and VH domains of another fragment, thereby forming twoantigen-binding sites. Another strategy for making bispecific antibodyfragments by the use of single-chain Fv (sFv) dimers has also beenreported. See, Gruber et al., J. Immunol., 152:5368 (1994).

Antibodies with more than two valencies are contemplated. For example,trispecific antibodies can be prepared. See, e.g., Tun et al. J.Immunol. 147: 60 (1991).

Multivalent Antibodies

A multivalent antibody may be internalized (and/or catabolized) fasterthan a bivalent antibody by a cell expressing an antigen to which theantibodies bind. The antibodies of the present disclosure may bemultivalent antibodies (which are other than of the IgM class) withthree or more antigen binding sites (e.g., tetravalent antibodies),which may be produced by recombinant expression of nucleic acid encodingthe polypeptide chains of the antibody. The multivalent antibody maycomprise a dimerization domain and three or more antigen binding sites.A preferred dimerization domain may comprise (or consist of) an Fcregion or a hinge region. In this scenario, the antibody will comprisean Fc region and three or more antigen binding sites amino-terminal tothe Fe region. A preferred multivalent antibody may comprise (or consistof) three to about eight, but preferably four, antigen binding sites.The multivalent antibody comprises at least one polypeptide chain (andpreferably two polypeptide chains), wherein the polypeptide chain(s)comprise two or more variable domains. For instance, the polypeptidechain(s) may comprise VD1-(X1)n-VD2-(X2)n-Fc, wherein VD1 is a firstvariable domain, VD2 is a second variable domain, Fc is one polypeptidechain of an Fc region, X1 and X2 represent an amino acid or polypeptide,and n is 0 or 1. For instance, the polypeptide chain(s) may comprise:VH-CH1-flexible linker-VH-CH1-Fc region chain; or VH-CH1-VH-CH1-Fcregion chain. A multivalent antibody may preferably further comprises atleast two (and preferably four) light chain variable domainpolypeptides. A multivalent antibody may, for instance, comprise fromabout two to about eight light chain variable domain polypeptides. Thelight chain variable domain polypeptides may comprise a light chainvariable domain and, optionally, further comprise a CL domain.

Antibody Variants

In some embodiments, amino acid sequence modification(s) of thehumanized antibodies comprising an ultralong CDR3 as described hereinare contemplated. For example, it may be desirable to improve thebinding affinity and/or other biological properties of the antibody.Amino acid sequence variants of the antibody are prepared by introducingappropriate nucleotide changes into the antibody nucleic acid, or bypeptide synthesis. Such modifications include, for example, deletionsfrom, and/or insertions into and/or substitutions of, residues withinthe amino acid sequences of the antibody. Any combination of deletion,insertion, and substitution is made to arrive at the final construct,provided that the final construct possesses the desired characteristics.The amino acid alterations may be introduced in the subject antibodyamino acid sequence at the time that sequence is made.

A useful method for identification of certain residues or regions of theantibody that are preferred locations for mutagenesis is called “alaninescanning mutagenesis” as described by Cunningham and Wells (1989)Science, 244:1081-1085. Here, a residue or group of target residues areidentified (e.g., charged residues such as arg, asp, his, lys, and glu)and replaced by a neutral or negatively charged amino acid (mostpreferably alanine or polyalanine) to affect the interaction of theamino acids with antigen. Those amino acid locations demonstratingfunctional sensitivity to the substitutions then are refined byintroducing further or other variants at, or for, the sites ofsubstitution. Thus, while the site for introducing an amino acidsequence variation is predetermined, the nature of the mutation per seneed not be predetermined. For example, to analyze the performance of amutation at a given site, ala scanning or random mutagenesis isconducted at the target codon or region and the expressedimmunoglobulins are screened for the desired activity.

Amino acid sequence insertions include amino- and/or carboxyl-terminalfusions ranging in length from one residue to polypeptides containing ahundred or more residues, as well as intrasequence insertions of singleor multiple amino acid residues. Examples of terminal insertions includean antibody with an N-terminal methionyl residue or the antibody fusedto a cytotoxic polypeptide. Other insertional variants of the antibodymolecule include the fusion to the N- or C-terminus of the antibody toan enzyme (e.g., for ADEPT) or a polypeptide which increases the serumhalf-life of the antibody.

Glycosylation of polypeptides is typically either N-linked or O-linked.N-linked refers to the attachment of the carbohydrate moiety to the sidechain of an asparagine residue. The tripeptide sequencesasparagine-X-serine and asparagine-X-threonine, where X is any aminoacid except proline, are the recognition sequences for enzymaticattachment of the carbohydrate moiety to the asparagine side chain.Thus, the presence of either of these tripeptide sequences in apolypeptide creates a potential glycosylation site. O-linkedglycosylation refers to the attachment of one of the sugarsN-aceylgalactosamine, galactose, or xylose to a hydroxyamino acid, mostcommonly serine or threonine, although 5-hydroxyproline or5-hydroxylysine may also be used.

Addition of glycosylation sites to the antibody is convenientlyaccomplished by altering the amino acid sequence such that it containsone or more of the above-described tripeptide sequences (for N-linkedglycosylation sites). The alteration may also be made by the additionof, or substitution by, one or more serine or threonine residues to thesequence of the original antibody (for O-linked glycosylation sites).

Where the antibody comprises an Fc region, the carbohydrate attachedthereto may be altered. For example, antibodies with a maturecarbohydrate structure that lacks fucose attached to an Fc region of theantibody have been described (see, e.g., US 2003/0157108, US2004/0093621. Antibodies with a bisecting N-acetylglucosamine (GlcNAc)in the carbohydrate attached to an Fc region of the antibody have beendescribed (see, e.g., WO 2003/011878, and U.S. Pat. No. 6,602,684).Antibodies with at least one galactose residue in the oligosaccharideattached to an Fc region of the antibody WO 1997/30087; see, also, WO1998/58964 and WO 1999/22764 concerning antibodies with alteredcarbohydrate attached to the Fc region thereof). Antigen-bindingmolecules with modified glycosylation have been described (see, e.g., WO99/54342, U.S. Pat. Nos. 6,602,684 and 7,517,670, and US 2004/0072290;see also, e.g., U.S. Pat. Nos. 7,214,775 and 7,682,610).

The preferred glycosylation variant herein comprises an Fc region,wherein a carbohydrate structure attached to the Fc region lacks fucose.Such variants have improved ADCC function. Optionally, the Fc regionfurther comprises one or more amino acid substitutions therein whichfurther improve ADCC, for example, substitutions at positions 298, 333,and/or 334 of the Fc region (Eu numbering of residues). Examples ofpublications related to “defucosylated” or “fucose-deficient” antibodiesinclude: US 2003/0157108; WO 2000/61739; WO 2001/29246; US 2003/0115614(now U.S. Pat. No. 6,946,292) US 2002/0164328 (now U.S. Pat. No.7,064,191); US 2004/0093621; US 2004/0132140; US 2004/0110704; US2004/0110282 (now U.S. Pat. No. 7,749,753); US 2004/0109865; WO2003/085119; WO 2003/084570; WO 2005/035586; WO 2005/035778;WO2005/053742; Okazaki et al. J. Mol. Biol. 336:1239-1249 (2004);Yamane-Ohnuki et al. Biotech. Bioeng. 87: 614 (2004). Examples of celllines producing defucosylated antibodies include Lec13 CHO cellsdeficient in protein fucosylation (Ripka et al. Arch. Biochem. Biophys.249:533-545 (1986); US Pat Appl No US 2003/0157108 A1, Presta, L; and WO2004/056312 A1, Adams et al., especially at Example 11), and knockoutcell lines, such as alpha-1,6-fucosyltransferase gene, FUT8, knockoutCHO cells (Yamane-Ohnuki et al. Biotech. Bioeng. 87: 614 (2004)).

Another type of variant is an amino acid substitution variant. Thesevariants have at least one amino acid residue in the antibody moleculereplaced by a different residue. The sites of greatest interest forsubstitutional mutagenesis include the hypervariable regions, but FRalterations are also contemplated. Conservative substitutions are shownin Table 2 under the heading of “preferred substitutions”. If suchsubstitutions result in a change in biological activity, then moresubstantial changes, denominated “exemplary substitutions”, or asfurther described below in reference to amino acid classes, may beintroduced and the products screened.

Original Exemplary Preferred Residue Substitutions Substitutions Ala (A)Val; Leu; Ile Val Arg (R) Lys; Gln; Asn Lys Asn (N) Gln; His; Asp, Lys;Arg Gln Asp (D) Glu; Asn Glu Cys (C) Ser; Ala Ser Gln (Q) Asn; Glu AsnGlu (E) Asp; Gln Asp Gly (G) Ala Ala His (H) Asn; Gln; Lys; Arg Arg Ile(I) Leu; Val; Met; Ala; Phe; Norleucine Leu Leu (L) Norleucine; Ile;Val; Met; Ala; Phe Ile Lys (K) Arg; Gln; Asn Arg Met (M) Leu; Phe; IleLeu Phe (F) Trp; Leu; Val; Ile; Ala; Tyr Tyr Pro (P) Ala Ala Ser (S) ThrThr Thr (T) Val; Ser Ser Trp (W) Tyr; Phe Tyr Tyr (Y) Trp; Phe; Thr; SerPhe Val (V) Ile; Leu; Met; Phe; Ala; Norleucine Leu

Substantial modifications in the biological properties of the antibodyare accomplished by selecting substitutions that differ significantly intheir effect on maintaining (a) the structure of the polypeptidebackbone in the area of the substitution, for example, as a sheet orhelical conformation, (b) the charge or hydrophobicity of the moleculeat the target site, or (c) the bulk of the side chain. Naturallyoccurring residues are divided into groups based on common side-chainproperties: (1) hydrophobic: norleucine, met, ala, val, leu, ile; (2)neutral hydrophilic: Cys, Ser, Thr, Asn, Gln; (3) acidic: asp, glu; (4)basic: his, lys, arg; (5) residues that influence chain orientation:gly, pro; and (6) aromatic: trp, tyr, phe.

Non-conservative substitutions will entail exchanging a member of one ofthese classes for another class.

One type of substitutional variant involves substituting one or morehypervariable region residues of a parent antibody (e.g., a humanized orhuman antibody). Generally, the resulting variant(s) selected forfurther development will have improved biological properties relative tothe parent antibody from which they are generated. A convenient way forgenerating such substitutional variants involves affinity maturationusing phage display. Briefly, several hypervariable region sites (e.g.,6-7 sites) are mutated to generate all possible amino acid substitutionsat each site. The antibodies thus generated are displayed fromfilamentous phage particles as fusions to the gene III product of M13packaged within each particle. The phage-displayed variants are thenscreened for their biological activity (e.g., binding affinity) asherein disclosed. In order to identify candidate hypervariable regionsites for modification, alanine scanning mutagenesis can be performed toidentify hypervariable region residues contributing significantly toantigen binding. Alternatively, or additionally, it may be beneficial toanalyze a crystal structure of the antigen-antibody complex to identifycontact points between the antibody and antigen. Such contact residuesand neighboring residues are candidates for substitution according tothe techniques elaborated herein. Once such variants are generated, thepanel of variants is subjected to screening as described herein andantibodies with superior properties in one or more relevant assays maybe selected for further development.

Nucleic acid molecules encoding amino acid sequence variants of theantibody are prepared by a variety of methods known in the art. Thesemethods include, but are not limited to, isolation from a natural source(in the case of naturally occurring amino acid sequence variants) orpreparation by oligonucleotide-mediated (or site-directed) mutagenesis,PCR mutagenesis, and cassette mutagenesis of an earlier prepared variantor a non-variant version of the antibody.

It may be desirable to introduce one or more amino acid modifications inan Fc region of the immunoglobulin polypeptides disclosed herein,thereby generating a Fc region variant. The Fc region variant maycomprise a human Fc region sequence (e.g., a human IgG1, IgG2, IgG3 orIgG4 Fc region) comprising an amino acid modification (e.g., asubstitution) at one or more amino acid positions including that of ahinge cysteine.

In accordance with this description and the teachings of the art, it iscontemplated that in some embodiments, an antibody used in methodsdisclosed herein may comprise one or more alterations as compared to thewild type counterpart antibody, e.g., in the Fc region. These antibodieswould nonetheless retain substantially the same characteristics requiredfor therapeutic utility as compared to their wild type counterpart. Forexample, it is thought that certain alterations can be made in the Fcregion that would result in altered (e.g., either improved ordiminished) Clq binding and/or Complement Dependent Cytotoxicity (CDC),e.g., as described in WO99/51642. See also Duncan & Winter Nature322:738-40 (1988); U.S. Pat. No. 5,648,260; U.S. Pat. No. 5,624,821; andWO94/29351 concerning other examples of Fc region variants. WO00/42072and WO 2004/056312 describe antibody variants with improved ordiminished binding to FcRs. See, also, Shields et al. J. Biol. Chem.9(2): 6591-6604 (2001). Antibodies with increased half lives andimproved binding to the neonatal Fc receptor (FcRn), which isresponsible for the transfer of maternal IgGs to the fetus (Guyer etal., J. Immunol. 117:587 (1976) and Kim et al., J. Immunol. 24:249(1994)), are described in US2005/0014934 (Hinton et al.). Theseantibodies comprise an Fc reg on with one or more substitutions thereinwhich improve binding of the Fc region to FcRn. Polypeptide variantswith altered Fc region amino acid sequences and increased or decreasedClq binding capability are described in U.S. Pat. No. 6,194,551,WO99/51642. See, also, Idusogie et al. J. Immunol. 164:4178-4184 (2000).

In certain embodiments, the present disclosure contemplates an antibodyvariant that possesses some but not all effector functions, which makeit a desirable candidate for applications in which the half life of theantibody in vivo is important yet certain effector functions (such ascomplement and ADCC) are unnecessary or deleterious. In vitro and/or invivo cytotoxicity assays can be conducted to confirm thereduction/depletion of CDC and/or ADCC activities. For example, Fcreceptor (FcR) binding assays can be conducted to ensure that theantibody lacks FcyR binding (hence likely lacking ADCC activity), butretains FcRn binding ability. The primary cells for mediating ADCC, NKcells, express FcyRIII only, whereas monocytes express FcyRI, FcyRII andFcyRIII. FcR expression on hematopoietic cells is summarized in Table 3on page 464 of Ravetch and Kinet, Annu. Rev. Immunol. 9:457-492 (1991).Non-limiting examples of in vitro assays to assess ADCC activity of amolecule of interest is described in U.S. Pat. No. 5,500,362 (see, e.g.Hellstrom, I. et al. Proc. Nat'l Acad. Sci. USA 83:7059-7063 (1986)) andHellstrom, I et al., Proc. Nat'l Acad. Sci. USA 82:1499-1502 (1985);U.S. Pat. No. 5,821,337 (see, Bruggemann, M. et al., Exp. Med.166:1351-1361 (1987)). Alternatively, non-radioactive assays methods maybe employed (see, for example, ACTITM non-radioactive cytotoxicity assayfor flow cytometry (CellTecl1r1ology, Inc. Mountain View, Calif.; andCytoTox 96® non-radioactive cytotoxicity assay (Promega, Madison, Wis.).Useful effector cells for such assays include peripheral bloodmononuclear cells (PBMC) and Natural Killer (NK) cells. Alternatively,or additionally, ADCC activity of the molecule of interest may beassessed in vivo, e.g., in a animal model such as that disclosed inClynes et al. Proc. Nat'l Acad. Sci. USA 95:652-656 (1998). C1q bindingassays may also be carried out to confirm that the antibody is unable tobind Clq and hence lacks CDC activity. See, e.g., C1q and C3c bindingELISA in WO 2006/029879 and WO 2005/100402. To assess complementactivation, a CDC assay may be performed (see, for example,Gazzano-Santoro et al., Immunol. Methods 202:163 (1996); Cragg, M. S. etal., Blood 101:1045-1052 (2003); and Cragg, M. S, and M. J. Glennie,Blood 103:27382743 (2004)). FcRn binding and in vivo clearance/half lifedeterminations can also be performed using methods known in the art(see, e.g., Petkova, S. B. et al., Int'l Immunol. 18(12):1759-1769(2006)).

Antibodies with reduced effector function include those withsubstitution of one or more of Fc region residues 238, 265, 269, 270,297, 327 and 329 (U.S. Pat. No. 6,737,056). Such Fc mutants include Fcmutants with substitutions at two or more of amino acid positions 265,269, 270, 297 and 327, including the so-called “DANA” Fc mutant withsubstitution of residues 265 and 297 to alanine (U.S. Pat. No.7,332,581).

Certain antibody variants with improved or diminished binding to FcRsare described. (See, e.g., U.S. Pat. No. 6,737,056; WO 2004/056312, andShields et al., Biol. Chem. 9(2): 6591-6604 (2001).)

In certain embodiments, an antibody variant comprises an Fc region withone or more amino acid substitutions which improve ADCC, e.g.,substitutions at positions 298, 333, and/or 334 of the Fc region (EUnumbering of residues).

In some embodiments, alterations are made in the Fc region that resultin altered (i.e., either improved or diminished) C1q binding and/orComplement Dependent Cytotoxicity (CDC), e.g., as described in U.S. Pat.No. 6,194,551, WO 99/51642, and Idusogie et al. Immunol. 164: 41784184(2000).

Antibodies with increased half lives and improved binding to theneonatal Fc receptor (FcRn), which is responsible for the transfer ofmaternal IgGs to the fetus (Guyer et al., Immunol. 117:587 (1976) andKim et al., Immunol. 24:249 (1994)), are described in US2005/0014934A1(Hinton et al.). Those antibodies comprise an Fc region with one or moresubstitutions therein which improve binding of the Fc region to FcRn.Such Fc variants include those with substitutions at one or more of Fcregion residues: 238, 256, 265, 272, 286, 303, 305, 307, 311, 312, 317,340, 356, 360, 362, 376, 378, 380, 382, 413, 424 or 434, e.g.,substitution of Fc region residue 434 (U.S. Pat. No. 7,371,826).

See also Duncan & Winter, Nature 322:738-40 (1988); U.S. Pat. No.5,648,260; U.S. Pat. No. 5,624,821; and WO 94/29351 concerning otherexamples of Fc region variants.

Antibody Derivatives

The humanized antibodies comprising an ultralong CDR3 as disclosedherein may be further modified to contain additional nonproteinaceousmoieties that are known in the art and readily available. Preferably,the moieties suitable for derivatization of the antibody are watersoluble polymers. Non-limiting examples of water soluble polymersinclude, but are not limited to, polyethylene glycol (PEG), copolymersof ethylene glycol/propylene glycol, carboxymethylcellulose, dextran,polyvinyl alcohol, polyvinyl pyrrolidone, poly-1,3-dioxolane,poly-1,3,6-trioxane, ethylene/maleic anhydride copolymer, polyaminoacids(either homopolymers or random copolymers), and dextran or poly(n-vinylpyrrolidone)polyethylene glycol, propropylene glycol homopolymers,prolypropylene oxide/ethylene oxide co-polymers, polyoxyethylatedpolyols (e.g., glycerol), polyvinyl alcohol, and mixtures thereof.Polyethylene glycol propionaldehyde may have advantages in manufacturingdue to its stability in water. The polymer may be of any molecularweight, and may be branched or unbranched. The number of polymersattached to the antibody may vary, and if more than one polymers areattached, they can be the same or different molecules. In general, thenumber and/or type of polymers used for derivatization can be determinedbased on considerations including, but not limited to, the particularproperties or functions of the antibody to be improved, whether theantibody derivative will be used in a therapy under defined conditions,etc.

Vectors, Host Cells and Recombinant Methods

For recombinant production of an antibody or fragment thereof asdisclosed herein, the nucleic acid encoding it is isolated and insertedinto a replicable vector for further cloning (amplification of the DNA)or for expression. DNA encoding the antibody is readily isolated andsequenced using conventional procedures (e.g., by using oligonucleotideprobes that are capable of binding specifically to genes encoding theheavy and light chains of the antibody). In an exemplary embodiment,nucleic acid encoding a humanized antibody comprising an ultralong CDR3,a variable region comprising an ultralong CDR3, or an ultralong CDR3, isisolated and inserted into a replicable vector for further cloning(amplification of the DNA) or for expression. Many vectors areavailable. The choice of vector depends in part on the host cell to beused. Generally, preferred host cells are of either prokaryotic oreukaryotic (generally mammalian) origin. It will be appreciated thatconstant regions of any isotype can be used for this purpose, includingIgG, IgM, IgA, IgD, and IgE constant regions, and that such constantregions can be obtained from any human or animal species.

Expression vectors containing regulatory elements from eukaryoticviruses are typically used in eukaryotic expression vectors, e.g., SV40vectors, papilloma virus vectors, and vectors derived from Epstein-Barrvirus. Other exemplary eukaryotic vectors include pMSG, pAV009/A+,pMTO10/A+, pMAMneo-5, baculovirus pDSVE, and any other vector allowingexpression of proteins under the direction of the CMV promoter, SV40early promoter, SV40 later promoter, metallothionein promoter, murinemammary tumor virus promoter, Rous sarcoma virus promoter, polyhedrinpromoter, or other promoters shown effective for expression ineukaryotic cells.

Some expression systems have markers that provide gene amplificationsuch as thymidine kinase and dihydrofolate reductase. Alternatively,high yield expression systems not involving gene amplification are alsosuitable, such as using a baculovirus vector in insect cells, with anucleic acid sequence encoding a partially human ultralong CDR3 antibodychain under the direction of the polyhedrin promoter or other strongbaculovirus promoters.

a. Generating Antibodies Using Prokaryotic or Eukaryotic Host Cells:

i. Vector Construction

Polynucleotide sequences encoding polypeptide components of theantibodies disclosed herein can be obtained using standard recombinanttechniques. Desired polynucleotide sequences may be isolated andsequenced from antibody producing cells such as hybridoma cells.Alternatively, polynucleotides can be synthesized using nucleotidesynthesizer or PCR techniques. Once obtained, sequences encoding thepolypeptides are inserted into a recombinant vector capable ofreplicating and expressing heterologous polynucleotides in prokaryotichosts. Many vectors that are available and known in the art can be usedfor the purpose of the present disclosure. Selection of an appropriatevector will depend mainly on the size of the nucleic acids to beinserted into the vector and the particular host cell to be transformedwith the vector. Each vector contains various components, depending onits function (amplification or expression of heterologouspolynucleotide, or both) and its compatibility with the particular hostcell in which it resides. The vector components generally include, butare not limited to: an origin of replication, a selection marker gene, apromoter, a ribosome binding site (RBS), a signal sequence, theheterologous nucleic acid insert and a transcription terminationsequence. Additionally, V regions comprising an ultralong CDR3 mayoptionally be fused to a C-region to produce an antibody comprisingconstant regions.

In general, plasmid vectors containing replicon and control sequenceswhich are derived from species compatible with the host cell are used inconnection with these hosts. The vector ordinarily carries a replicationsite, as well as marking sequences which are capable of providingphenotypic selection in transformed cells. For example, E. coli istypically transformed using pBR322, a plasmid derived from an E. colispecies. pBR322 contains genes encoding ampicillin (Amp) andtetracycline (Tet) resistance and thus provides easy means foridentifying transformed cells. pBR322, its derivatives, or othermicrobial plasmids or bacteriophage may also contain, or be modified tocontain, promoters which can be used by the microbial organism forexpression of endogenous proteins. Examples of pBR322 derivatives usedfor expression of particular antibodies have been described (see, e.g.,U.S. Pat. No. 5,648,237).

In addition, phage vectors containing replicon and control sequencesthat are compatible with the host microorganism can be used astransforming vectors in connection with these hosts. For example,bacteriophage such as λGEM™-11 may be utilized in making a recombinantvector which can be used to transform susceptible host cells such as E.coli LE392.

The expression vectors disclosed herein may comprise two or morepromoter-cistron pairs, encoding each of the polypeptide components. Apromoter is an untranslated regulatory sequence located upstream (5′) toa cistron that modulates its expression. Prokaryotic promoters typicallyfall into two classes, inducible and constitutive. Inducible promoter isa promoter that initiates increased levels of transcription of thecistron under its control in response to changes in the culturecondition, e.g., the presence or absence of a nutrient or a change intemperature.

A large number of promoters recognized by a variety of potential hostcells are well known. The selected promoter can be operably linked tocistron DNA encoding the light or heavy chain by removing the promoterfrom the source DNA via restriction enzyme digestion and inserting theisolated promoter sequence into the vector disclosed herein. Both thenative promoter sequence and many heterologous promoters may be used todirect amplification and/or expression of the target genes. In someembodiments, heterologous promoters are utilized, as they generallypermit greater transcription and higher yields of expressed target geneas compared to the native target polypeptide promoter.

Promoters suitable for use with prokaryotic hosts include: an ara Bpromoter, a PhoA promoter, β-galactamase and lactose promoter systems, atryptophan (trp) promoter system and hybrid promoters such as the tac orthe trc promoter. However, other promoters that are functional inbacteria (such as other known bacterial or phage promoters) are suitableas well. Their nucleotide sequences have been published, therebyenabling a skilled worker operably to ligate them to cistrons encodingthe target light and heavy chains (e.g., Siebenlist et al. (1980) Cell20: 269) using linkers or adaptors to supply any required restrictionsites.

Suitable bacterial promoters are well known in the art and fullydescribed in scientific literature such as Sambrook and Russell, supra,and Ausubel et al, supra. Bacterial expression systems for expressingantibody chains of the recombinant catalytic polypeptide are availablein, e.g., E. coli, Bacillus sp., and Salmonella (Palva et al., Gene,22:229-235 (1983); Mosbach et al., Nature, 302:543-545 (1983)).

In one aspect disclosed herein, each cistron within the recombinantvector comprises a secretion signal sequence component that directstranslocation of the expressed polypeptides across a membrane. Ingeneral, the signal sequence may be a component of the vector, or it maybe a part of the target polypeptide DNA that is inserted into thevector. The signal sequence should be one that is recognized andprocessed (e.g., cleaved by a signal peptidase) by the host cell. Forprokaryotic host cells that do not recognize and process the signalsequences native to the heterologous polypeptides, the signal sequenceis substituted by a prokaryotic signal sequence selected, for examplePelB, OmpA, alkaline phosphatase, penicillinase, Ipp, or heat-stableenterotoxin II (STII) leaders, LamB, PhoE, and MBP. In one embodimentdisclosed herein, the signal sequences used in both cistrons of theexpression system are STII signal sequences or variants thereof.

In another aspect, the production of the immunoglobulins according tothe disclosure can occur in the cytoplasm of the host cell, andtherefore does not require the presence of secretion signal sequenceswithin each cistron. In that regard, immunoglobulin light and heavychains are expressed, folded and assembled to form functionalimmunoglobulins within the cytoplasm. Certain host strains (e.g., the E.coli trxB-strains) provide cytoplasm conditions that are favorable fordisulfide bond formation, thereby permitting proper folding and assemblyof expressed protein subunits (see e.g., Proba and Pluckthun Gene,159:203 (1995)).

Suitable host cells for cloning or expression of antibody-encodingvectors include prokaryotic or eukaryotic cells described herein. In oneembodiment, the host cell is eukaryotic, e.g. a Chinese Hamster Ovary(CHO) cell, Human Embryonic Kidney (HEK) cell or lymphoid cell (e.g.,YO, NSO, Sp20 cell). For example, antibodies may be produced inbacteria, in particular when glycosylation and Fc effector function arenot needed. For expression of antibody fragments and polypeptides inbacteria, see, e.g., U.S. Pat. Nos. 5,648,237, 5,789,199, and 5,840,523.(See also Charlton, Methods in Molecular Biology, Vol. 248 (B. K. C. Lo,ed., Humana Press, Totowa, N.J., 2003), pp. 245-254, describingexpression of antibody fragments in E. coli.) After expression, theantibody may be isolated from the bacterial cell paste in a solublefraction and can be further purified. In addition to prokaryotes,eukaryotic microbes such as filamentous fungi or yeast are suitablecloning or expression hosts for antibody-encoding vectors, includingfungi and yeast strains whose glycosylation pathways have been“humanized,” resulting in the production of an antibody with a partiallyor fully human glycosylation pattern. See Gemgross, Nat. Biotech. 22:1409-1414 (2004), and Li et al., Nat. Biotech. 24:210-215 (2006).Suitable host cells for the expression of glycosylated antibody are alsoderived from multicellular organisms (invertebrates and vertebrates).Examples of invertebrate cells include plant and insect cells. Numerousbaculoviral strains have been identified which may be used inconjunction with insect cells, particularly for transfection ofSpodoptera frugiperda cells. These examples are illustrative rather thanlimiting. Methods for constructing derivatives of any of theabove-mentioned bacteria having defined genotypes are known in the artand described in, for example, Bass et al., Proteins, 8:309-314 (1990).It is generally necessary to select the appropriate bacteria taking intoconsideration replicability of the replicon in the cells of a bacterium.For example, E. coli, Serratia, or Salmonella species can be suitablyused as the host when well known plasmids such as pBR322, pBR325,pACYC177, or pKN410 are used to supply the replicon. Typically the hostcell should secrete minimal amounts of proteolytic enzymes, andadditional protease inhibitors may desirably be incorporated in the cellculture.

Plant cell cultures can also be utilized as hosts. See, e.g. U.S. Pat.Nos. 5,959,177, 6,040,498, 6,420,548, 7,125, 978, and 6,417,429(describing PLANTIBODIES™ technology for producing antibodies intransgenic plants). Vertebrate cells may also be used as hosts. Forexample, mammalian cell lines that are adapted to grow in suspension maybe useful. Other examples of useful mammalian host cell lines are monkeykidney CV1 line transformed by SV40 (COS-7); human embryonic kidney line(293 or 293 cells as described, e.g., in Graham et al., Gen VII'0I.36:59 (1977)); baby hamster kidney cells (BHK); mouse sertoli cells (TM4cells as described, e.g., in Mather, Biol. Reprod. 23:243-251 (1980));monkey kidney cells (CV1); African green monkey kidney cells (VERO-76);human cervical carcinoma cells (HELA); canine kidney cells (MDCK;buffalo rat liver cells (BRL 3A); human lung cells (W138); human livercells (Hep G2); mouse mammary tumor (MMT 060562); TR1 cells, asdescribed, e.g., in Mather et al., Annals Nl'. Acad. Sci. 383:44-68(1982); MRC 5 cells; and FS4 cells. Other useful mammalian host celllines include Chinese hamster ovary (CHO) cells, including DHFR′ CHOcells (Urlaub et al., Proc. Natl. Acad. Sci. USA 77:4216 (1980)); andmyeloma cell lines such as YO, NSO and Sp2/0. For a review of certainmammalian host cell lines suitable for antibody production, see, e.g.,Yazaki and Wu, Methods in Molecular Biology, Vol. 248 (B. K. C. Lo, ed.,Humana Press, Totowa, N.]), pp. 255-268 (2003).

In one such embodiment, a host cell comprises (e.g., has beentransformed with): (1) a vector comprising a nucleic acid that encodesan amino acid sequence comprising the VL of the antibody and an aminoacid sequence comprising the VH of the antibody, or (2) a first vectorcomprising a nucleic acid that encodes an amino acid sequence comprisingthe VL of the antibody and a second vector comprising a nucleic acidthat encodes an amino acid sequence comprising the VH of the antibody.

ii. Antibody Production

For recombinant production of a partially human ultralong CDR3 antibody,nucleic acid encoding a humanized antibody comprising an ultralong CDR3is inserted into one or more expression vectors for further cloningand/or expression in a host cell. Such nucleic acid may be readilyisolated and sequenced using conventional procedures (e.g., by usingoligonucleotide probes that are capable of binding specifically to genesencoding the heavy and light chains of the antibody). Host cells aretransformed with such expression vectors and cultured in conventionalnutrient media modified as appropriate for inducing promoters, selectingtransformants, or amplifying the genes encoding the desired sequences.

Transformation means introducing DNA into the prokaryotic host so thatthe DNA is replicable, either as an extrachromosomal element or bychromosomal integrant. Depending on the host cell used, transformationis done using standard techniques appropriate to such cells. The calciumtreatment employing calcium chloride is generally used for bacterialcells that contain substantial cell-wall barriers. Another method fortransformation employs polyethylene glycol/DMSO. Yet another techniqueused is electroporation.

Prokaryotic cells used to produce the polypeptides disclosed herein aregrown in media known in the art and suitable for culture of the selectedhost cells. Examples of suitable media include luria broth (LB) plusnecessary nutrient supplements. In some embodiments, the media alsocontains a selection agent, chosen based on the construction of theexpression vector, to selectively permit growth of prokaryotic cellscontaining the expression vector. For example, ampicillin is added tomedia for growth of cells expressing ampicillin resistant gene.

Any necessary supplements besides carbon, nitrogen, and inorganicphosphate sources may also be included at appropriate concentrationsintroduced alone or as a mixture with another supplement or medium suchas a complex nitrogen source. Optionally the culture medium may containone or more reducing agents selected from the group consisting ofglutathione, cysteine, cystamine, thioglycollate, dithioerythritol anddithiothreitol.

The prokaryotic host cells are cultured at suitable temperatures. For E.coli growth, for example, the preferred temperature ranges from about20° C. to about 39° C., more preferably from about 25° C. to about 37°C., even more preferably at about 30° C. The pH of the medium may be anypH ranging from about 5 to about 9, depending mainly on the hostorganism. For E. coli, the pH is preferably from about 6.8 to about 7.4,and more preferably about 7.0.

If an inducible promoter is used in the expression vector disclosedherein, protein expression is induced under conditions suitable for theactivation of the promoter. For example, an ara B or phoA promoter maybe used for controlling transcription of the polypeptides. A variety ofinducers may be used, according to the vector construct employed, as isknown in the art.

The expressed polypeptides of the present disclosure are secreted intoand recovered from the periplasm of the host cells or transported intothe culture media. Protein recovery from the periplasm typicallyinvolves disrupting the microorganism, generally by such means asosmotic shock, sonication or lysis. Once cells are disrupted, celldebris or whole cells may be removed by centrifugation or filtration.The proteins may be further purified, for example, by affinity resinchromatography. Alternatively, proteins that are transported into theculture media may be isolated therein. Cells may be removed from theculture and the culture supernatant being filtered and concentrated forfurther purification of the proteins produced. The expressedpolypeptides can be further isolated and identified using commonly knownmethods such as polyacrylamide gel electrophoresis (PAGE) and Westernblot assay.

Antibody production may be conducted in large quantity by a fermentationprocess. Various large-scale fed-batch fermentation procedures areavailable for production of recombinant proteins. Large-scalefermentations have at least 1000 liters of capacity, preferably about1,000 to 100,000 liters of capacity. These fermentors use agitatorimpellers to distribute oxygen and nutrients, especially glucose (apreferred carbon/energy source). Small scale fermentation refersgenerally to fermentation in a fermentor that is no more thanapproximately 100 liters in volumetric capacity, and can range fromabout 1 liter to about 100 liters.

In a fermentation process, induction of protein expression is typicallyinitiated after the cells have been grown under suitable conditions to adesired density, e.g., an OD550 of about 180-220, at which stage thecells are in the early stationary phase. A variety of inducers may beused, according to the vector construct employed, as is known in the artand described above. Cells may be grown for shorter periods prior toinduction. Cells are usually induced for about 12-50 hours, althoughlonger or shorter induction time may be used.

To improve the production yield and quality of the polypeptidesdisclosed herein, various fermentation conditions can be modified. Forexample, to improve the proper assembly and folding of the secretedantibody polypeptides, additional vectors overexpressing chaperoneproteins, such as Dsb proteins (DsbA, DsbB, DsbC, DsbD and or DsbG) orFkpA (a peptidylprolyl cis,trans-isomerase with chaperone activity) maybe used to co-transform the host prokaryotic cells. The chaperoneproteins have been demonstrated to facilitate the proper folding andsolubility of heterologous proteins produced in bacterial host cells.(see e.g., Chen et al. (1999) J Bio Chem 274:19601-19605; U.S. Pat. No.6,083,715; U.S. Pat. No. 6,027,888; Bothmann and Pluckthun (2000) J.Biol. Chem. 275:17100-17105; Ramm and Pluckthun (2000) J. Biol. Chem.275:17106-17113; Arie et al. (2001) Mol. Microbiol. 39:199-210).

To minimize proteolysis of expressed heterologous proteins (especiallythose that are proteolytically sensitive), certain host strainsdeficient for proteolytic enzymes can be used for the presentdisclosure. For example, host cell strains may be modified to effectgenetic mutation(s) in the genes encoding known bacterial proteases suchas Protease III, OmpT, DegP, Tsp, Protease I, Protease Mi, Protease V,Protease VI and combinations thereof. Some E. coli protease-deficientstrains are available (see, e.g., Joly et al. (1998), supra; U.S. Pat.No. 5,264,365; U.S. Pat. No. 5,508,192; Hara et al., Microbial DrugResistance, 2:63-72 (1996)).

E. coli strains deficient for proteolytic enzymes and transformed withplasmids overexpressing one or more chaperone proteins may be used ashost cells in the expression systems disclosed herein.

iii. Antibody Purification

Standard protein purification methods known in the art can be employed.The following procedures are exemplary of suitable purificationprocedures: fractionation on immunoaffinity or ion-exchange columns,ethanol precipitation, reverse phase HPLC, chromatography on silica oron a cation-exchange resin such as DEAE, chromatofocusing, SDS-PAGE,ammonium sulfate precipitation, and gel filtration using, for example,Sephadex G-75.

In one aspect, Protein A immobilized on a solid phase is used forimmunoaffinity purification of the full length antibody productsdisclosed herein. Protein A is a 41 kD cell wall protein fromStaphylococcus aureas which binds with a high affinity to the Fc regionof antibodies (see, e.g., Lindmark et al (1983) J. Immunol. Meth.62:1-13). The solid phase to which Protein A is immobilized ispreferably a column comprising a glass or silica surface, morepreferably a controlled pore glass column or a silicic acid column. Insome applications, the column has been coated with a reagent, such asglycerol, in an attempt to prevent nonspecific adherence ofcontaminants.

As the first step of purification, the preparation derived from the cellculture as described above is applied onto the Protein A immobilizedsolid phase to allow specific binding of the antibody of interest toProtein A. The solid phase is then washed to remove contaminantsnon-specifically bound to the solid phase. Finally the antibody ofinterest is recovered from the solid phase by elution.

b. Generating Antibodies Using Eukaryotic Host Cells:

The vector components generally include, but are not limited to, one ormore of the following: a signal sequence, an origin of replication, oneor more marker genes, an enhancer element, a promoter, and atranscription termination sequence.

(i) Signal Sequence Component

A vector for use in a eukaryotic host cell may also contain a signalsequence or other polypeptide having a specific cleavage site at theN-terminus of the mature protein or polypeptide of interest. Theheterologous signal sequence selected preferably is one that isrecognized and processed (e.g., cleaved by a signal peptidase) by thehost cell. In mammalian cell expression, mammalian signal sequences aswell as viral secretory leaders, for example, the herpes simplex gDsignal, are available.

The DNA for such precursor region is ligated in reading frame to DNAencoding the antibody.

(ii) Origin of Replication

Generally, an origin of replication component is not needed formammalian expression vectors. For example, the SV40 origin may be usedonly because it contains the early promoter.

(iii) Selection Gene Component

Expression and cloning vectors may contain a selection gene, also termeda selectable marker. Typical selection genes encode proteins that (a)confer resistance to antibiotics or other toxins, e.g., ampicillin,neomycin, methotrexate, or tetracycline, (b) complement auxotrophicdeficiencies, where relevant, or (c) supply critical nutrients notavailable from complex media.

One example of a selection scheme utilizes a drug to arrest growth of ahost cell. Those cells that are successfully transformed with aheterologous gene produce a protein conferring drug resistance and thussurvive the selection regimen. Examples of such dominant selection usethe drugs neomycin, mycophenolic acid and hygromycin.

Another example of suitable selectable markers for mammalian cells arethose that enable the identification of cells competent to take up theantibody nucleic acid, such as DHFR, thymidine kinase, metallothionein-Iand -II, preferably primate metallothionein genes, adenosine deaminase,ornithine decarboxylase, etc.

For example, cells transformed with the DHFR selection gene are firstidentified by culturing all of the transformants in a culture mediumthat contains methotrexate (Mtx), a competitive antagonist of DHFR. Anappropriate host cell when wild-type DHFR is employed is the Chinesehamster ovary (CHO) cell line deficient in DHFR activity (e.g., ATCCCRL-9096).

Alternatively, host cells (particularly wild-type hosts that containendogenous DHFR) transformed or co-transformed with DNA sequencesencoding an antibody, wild-type DHFR protein, and another selectablemarker such as aminoglycoside 3′-phosphotransferase (APH) can beselected by cell growth in medium containing a selection agent for theselectable marker such as an aminoglycosidic antibiotic, e.g.,kanamycin, neomycin, or G418. See U.S. Pat. No. 4,965,199.

(iv) Promoter Component

Expression and cloning vectors usually contain a promoter that isrecognized by the host organism and is operably linked to the antibodypolypeptide nucleic acid. Promoter sequences are known for eukaryotes.Virtually alleukaryotic genes have an AT-rich region locatedapproximately 25 to 30 bases upstream from the site where transcriptionis initiated. Another sequence found 70 to 80 bases upstream from thestart of transcription of many genes is a CNCAAT region where N may beany nucleotide. At the 3′ end of most eukaryotic genes is an AATAAAsequence that may be the signal for addition of the poly A tail to the3′ end of the coding sequence. All of these sequences are suitablyinserted into eukaryotic expression vectors.

Antibody polypeptide transcription from vectors in mammalian host cellsis controlled, for example, by promoters obtained from the genomes ofviruses such as polyoma virus, fowlpox virus, adenovirus (such asAdenovirus 2), bovine papilloma virus, avian sarcoma virus,cytomegalovirus, a retrovirus, hepatitis-B virus and Simian Virus 40(SV40), from heterologous mammalian promoters, e.g., the actin promoteror an immunoglobulin promoter, from heat-shock promoters, provided suchpromoters are compatible with the host cell systems.

The early and late promoters of the SV40 virus are conveniently obtainedas an SV40 restriction fragment that also contains the SV40 viral originof replication. The immediate early promoter of the humancytomegalovirus is conveniently obtained as a HindIII E restrictionfragment. A system for expressing DNA in mammalian hosts using thebovine papilloma virus as a vector is disclosed in U.S. Pat. No.4,419,446. A modification of this system is described in U.S. Pat. No.4,601,978. Alternatively, the Rous Sarcoma Virus long terminal repeatcan be used as the promoter.

(v) Enhancer Element Component

Transcription of DNA encoding the antibody polypeptide of thisdisclosure by higher eukaryotes is often increased by inserting anenhancer sequence into the vector. Many enhancer sequences are now knownfrom mammalian genes (globin, elastase, albumin, α-fetoprotein, andinsulin). An enhancer from a eukaryotic cell virus may also be used.Examples include the SV40 enhancer on the late side of the replicationorigin (bp 100-270), the cytomegalovirus early promoter enhancer, thepolyoma enhancer on the late side of the replication origin, andadenovirus enhancers. See also Yaniv, Nature 297:17-18 (1982) onenhancing elements for activation of eukaryotic promoters. The enhancermay be spliced into the vector at a position 5′ or 3′ to the antibodypolypeptide-encoding sequence, but is preferably located at a site 5′from the promoter.

(vi) Transcription Termination Component

Expression vectors used in eukaryotic host cells will typically alsocontain sequences necessary for the termination of transcription and forstabilizing the mRNA. Such sequences are commonly available from the 5′and, occasionally 3′, untranslated regions of eukaryotic or viral DNAsor cDNAs. These regions contain nucleotide segments transcribed aspolyadenylated fragments in the untranslated portion of the mRNAencoding an antibody. One useful transcription termination component isthe bovine growth hormone polyadenylation region. See WO94/11026 and theexpression vector disclosed therein.

(vii) Selection and Transformation of Host Cells

Suitable host cells for cloning or expressing the DNA in the vectorsherein include higher eukaryote cells described herein, includingvertebrate host cells. Propagation of vertebrate cells in culture(tissue culture) has become a routine procedure. Examples of usefulmammalian host cell lines are monkey kidney CV1 line transformed by SV40(COS-7, ATCC CRL 1651); human embryonic kidney line (293 or 293 cellssubcloned for growth in suspension culture, Graham et al., J. Gen Virol.36:59 (1977)); baby hamster kidney cells (BHK, ATCC CCL 10); Chinesehamster ovary cells/−DHFR (CHO, Urlaub et al., Proc. Natl. Acad. Sci.USA 77:4216 (1980)); mouse sertoli cells (TM4, Mather, Biol. Reprod.23:243-251 (1980); monkey kidney cells (CV1 ATCC CCL 70); African greenmonkey kidney cells (VERO-76, ATCC CRL-1587); human cervical carcinomacells (HELA, ATCC CCL 2); canine kidney cells (MDCK, ATCC CCL 34);buffalo rat liver cells (BRL 3A, ATCC CRL 1442); human lung cells (W138,ATCC CCL 75); human liver cells (Hep G2, HB 8065); mouse mammary tumor(MMT 060562, ATCC CCL51); TRI cells (Mather et al., Annals N.Y. Acad.Sci. 383:44-68 (1982)); MRC 5 cells; FS4 cells; and a human hepatomaline (Hep G2).

Any of the well-known procedures for introducing foreign nucleotidesequences into host cells may be used. These include the use of calciumphosphate transfection, polybrene, protoplast fusion, electroporation,biolistics, liposomes, microinjection, plasma vectors, viral vectors andany of the other well known methods for introducing cloned genomic DNA,cDNA, synthetic DNA, or other foreign genetic material into a host cell(see, e.g., Sambrook and Russell, supra). It is only necessary that theparticular genetic engineering procedure used be capable of successfullyintroducing at least both genes into the host cell capable of expressinggermline antibody polypeptide.

Host cells are transformed with the above-described expression orcloning vectors for antibody production and cultured in conventionalnutrient media modified as appropriate for inducing promoters, selectingtransformants, or amplifying the genes encoding the desired sequences.

(viii) Culturing the Host Cells

The host cells used to produce an antibody of this disclosure may becultured in a variety of media. Commercially available media such asHam's F10 (Sigma), Minimal Essential Medium ((MEM), (Sigma), RPMI-1640(Sigma), and Dulbecco's Modified Eagle's Medium ((DMEM), Sigma) aresuitable for culturing the host cells. In addition, any of the mediadescribed in Ham et al., Meth. Enz. 58:44 (1979), Barnes et al., Anal.Biochem. 102:255 (1980), U.S. Pat. No. 4,767,704; 4,657,866; 4,927,762;4,560,655; or 5,122,469; WO 90/03430; WO 87/00195; or U.S. Pat. Reissue30,985 may be used as culture media for the host cells. Any of thesemedia may be supplemented as necessary with hormones and/or other growthfactors (such as insulin, transferrin, or epidermal growth factor),salts (such as sodium chloride, calcium, magnesium, and phosphate),buffers (such as HEPES), nucleotides (such as adenosine and thymidine),antibiotics (such as GENTAMYCIN™ drug), trace elements (defined asinorganic compounds usually present at final concentrations in themicromolar range), and glucose or an equivalent energy source. Any othernecessary supplements may also be included at appropriate concentrationsthat would be known to those skilled in the art. The culture conditions,such as temperature, pH, and the like, are those previously used withthe host cell selected for expression, and will be apparent to theordinarily skilled artisan.

(ix) Purification of Antibody

When using recombinant techniques, the antibody can be producedintracellularly, or directly secreted into the medium. If the antibodyis produced intracellularly, as a first step, the particulate debris,either host cells or lysed fragments, are removed, for example, bycentrifugation or ultrafiltration. Where the antibody is secreted intothe medium, supernatants from such expression systems are generallyfirst concentrated using a commercially available protein concentrationfilter, for example, an Amicon or Millipore Pellicon® ultrafiltrationunit. A protease inhibitor such as PMSF may be included in any of theforegoing steps to inhibit proteolysis and antibiotics may be includedto prevent the growth of adventitious contaminants.

The antibody composition prepared from the cells can be purified using,for example, hydroxylapatite chromatography, gel electrophoresis,dialysis, and affinity chromatography, with affinity chromatographybeing the preferred purification technique. The suitability of protein Aas an affinity ligand depends on the species and isotype of anyimmunoglobulin Fc domain that is present in the antibody. Protein A canbe used to purify antibodies that are based on human γ1, γ2, or γ4 heavychains (Lindmark et al., J. Immunol. Meth. 62:1-13 (1983)). Protein G isrecommended for all mouse isotypes and for human γ3 (Guss et al., EMBOJ. 5:15671575 (1986)). The matrix to which the affinity ligand isattached is most often agarose, but other matrices are available.Mechanically stable matrices such as controlled pore glass orpoly(styrenedivinyl)benzene allow for faster flow rates and shorterprocessing times than can be achieved with agarose. Where the antibodycomprises a CH3 domain, the Bakerbond ABX™ resin (J. T. Baker,Phillipsburg, N.J.) is useful for purification. Other techniques forprotein purification such as fractionation on an ion-exchange column,ethanol precipitation, Reverse Phase HPLC, chromatography on silica,chromatography on heparin SEPHAROSE™ chromatography on an anion orcation exchange resin (such as a polyaspartic acid column),chromatofocusing, SDS-PAGE, and ammonium sulfate precipitation are alsoavailable depending on the antibody to be recovered.

Soluble forms of antibody or fragment present either in the cytoplasm orreleased from the periplasmic space may be further purified usingmethods known in the art, for example Fab fragments are released fromthe bacterial periplasmic space by osmotic shock techniques.

If inclusion bodies comprising an antibody or fragment have formed, theycan often bind to the inner and/or outer cellular membranes and thuswill be found primarily in the pellet material after centrifugation. Thepellet material can then be treated at pH extremes or with chaotropicagent such as a detergent, guanidine, guanidine derivatives, urea, orurea derivatives in the presence of a reducing agent such asdithiothreitol at alkaline pH or tris carboxyethyl phosphine at acid pHto release, break apart, and solubilize the inclusion bodies. Thesoluble antibody or fragment can then be analyzed using gelelectrophoresis, immunoprecipitation or the like. If it is desired toisolate a solubilized antibody or antigen binding fragment isolation maybe accomplished using standard methods such as those set forth below andin Marston et al. (Meth. Enz., 182:264-275 (1990)).

Following any preliminary purification step(s), the mixture comprisingthe antibody of interest and contaminants may be subjected to low pHhydrophobic interaction chromatography using an elution buffer at a pHbetween about 2.5-4.5, preferably performed at low salt concentrations(e.g., from about 0-0.25 M salt).

In some cases, an antibody or fragment may not be biologically activeupon isolation. Various methods for “refolding” or converting apolypeptide to its tertiary structure and generating disulfide linkages,can be used to restore biological activity. Such methods includeexposing the solubilized polypeptide to a pH usually above 7 and in thepresence of a particular concentration of a chaotrope. The selection ofchaotrope is very similar to the choices used for inclusion bodysolubilization, but usually the chaotrope is used at a lowerconcentration and is not necessarily the same as chaotropes used for thesolubilization. In most cases the refolding/oxidation solution will alsocontain a reducing agent or the reducing agent plus its oxidized form ina specific ratio to generate a particular redox potential allowing fordisulfide shuffling to occur in the formation of the protein's cysteinebridge(s). Some of the commonly used redox couples includecysteine/cystamine, glutathione (GSH)/dithiobis GSH, cupric chloride,dithiothreitol (DTT)/dithiane DTT, and 2-mercaptoethanol (bME)/di-thio-b(ME). In many instances, a cosolvent may be used to increase theefficiency of the refolding, and common reagents used for this purposeinclude glycerol, polyethylene glycol of various molecular weights,arginine and the like.

Immunoconjugates

The disclosure also provides immunoconjugates (interchangeably termed“antibody-drug conjugates” or “ADC”), comprising any of the humanizedantibodies comprising an ultralong CDR3 as described herein conjugatedto a cytotoxic agent such as a chemotherapeutic agent, a drug, a growthinhibitory agent, a toxin (e.g., an enzymatically active toxin ofbacterial, fungal, plant, or animal origin, or fragments thereof), or aradioactive isotope (e.g., a radioconjugate).

The use of antibody-drug conjugates for the local delivery of cytotoxicor cytostatic agents. For example, drugs to kill or inhibit tumor cellsin the treatment of cancer (Syrigos and Epenetos (1999) AnticancerResearch 19:605-614; Niculescu-Duvaz and Springer (1997) Adv. Drg Del.Rev. 26:151-172; U.S. Pat. No. 4,975,278) allows targeted delivery ofthe drug moiety to tumors, and intracellular accumulation therein, wheresystemic administration of these unconjugated drug agents may result inunacceptable levels of toxicity to normal cells as well as the tumorcells sought to be eliminated (Baldwin et al., (1986) Lancet pp. (Mar.15, 1986):603-05; Thorpe, (1985) “Antibody Carriers Of Cytotoxic AgentsIn Cancer Therapy: A Review,” in Monoclonal Antibodies '84: BiologicalAnd Clinical Applications, A. Pinchera et al. (ed.s), pp. 475-506).Maximal efficacy with minimal toxicity is sought thereby. Bothpolyclonal antibodies and monoclonal antibodies have been reported asuseful in these strategies (Rowland et al., (1986) Cancer Immunol.Immunother., 21:183-87). Drugs used in these methods include daunomycin,doxorubicin, methotrexate, and vindesine (Rowland et al., (1986) Supra).Toxins used in antibody-toxin conjugates include bacterial toxins suchas diphtheria toxin, plant toxins such as ricin, small molecule toxinssuch as geldanamycin (Mandler et al (2000) Jour. of the Nat. CancerInst. 92(19):1573-1581; Mandler et al (2000) Bioorganic & Med. Chem.Letters 10: 1025-1028; Mandler et al (2002) Bioconjugate Chem.13:786-791), maytansinoids (EP 1391213; Liu et al., (1996) Proc. Natl.Acad. Sci. USA 93:8618-8623), and calicheamicin (Lode et al (1998)Cancer Res. 58:2928; Hinman et al (1993) Cancer Res. 53:3336-3342). Thetoxins may effect their cytotoxic and cytostatic effects by mechanismsincluding tubulin binding, DNA binding, or topoisomerase inhibition.Some cytotoxic drugs tend to be inactive or less active when conjugatedto large antibodies or protein receptor ligands.

ZEVALIN® (ibritumomab tiuxetan, Biogen/Idec) is an antibody-radioisotopeconjugate composed of a murine IgG1 kappa monoclonal antibody directedagainst the CD20 antigen found on the surface of normal and malignant Blymphocytes and ¹¹¹In or ⁹⁰Y radioisotope bound by a thiourealinker-chelator (Wiseman et al (2000) Eur. Jour. Nucl. Med.27(7):766-77; Wiseman et al (2002) Blood 99(12):4336-42; Witzig et al(2002) J. Clin. Oncol. 20(10):2453-63; Witzig et al (2002) J. Clin.Oncol. 20(15):3262-69). Although ZEVALIN has activity against B-cellnon-Hodgkin's Lymphoma (NHL), administration results in severe andprolonged cytopenias in most patients. MYLOTARG™ (gemtuzumab ozogamicin,Wyeth Pharmaceuticals), an antibody drug conjugate composed of a hu CD33antibody linked to calicheamicin, was approved in 2000 for the treatmentof acute myeloid leukemia by injection (Drugs of the Future (2000)25(7):686; U.S. Pat. Nos. 4,970,198; 5,079,233; 5,585,089; 5,606,040;5,693,762; 5,739,116; 5,767,285; 5,773,001). Cantuzumab mertansine(Immunogen, Inc.), an antibody drug conjugate composed of the huC242antibody linked via the disulfide linker SPP to the maytansinoid drugmoiety, DM1, is advancing into Phase II trials for the treatment ofcancers that express CanAg, such as colon, pancreatic, gastric, andothers. MLN-2704 (Millennium Pharm., BZL Biologics, Immunogen Inc.), anantibody drug conjugate composed of the anti-prostate specific membraneantigen (PSMA) monoclonal antibody linked to the maytansinoid drugmoiety, DM1, is under development for the potential treatment ofprostate tumors. The auristatin peptides, auristatin E (AE) andmonomethylauristatin (MMAE), synthetic analogs of dolastatin, wereconjugated to chimeric monoclonal antibodies cBR96 (specific to Lewis Yon carcinomas) and cAC10 (specific to CD30 on hematologicalmalignancies) (Doronina et al (2003) Nature Biotechnology 21(7):778-784)and are under therapeutic development.

Chemotherapeutic agents useful in the generation of immunoconjugates aredescribed herein. Enzymatically active toxins and fragments thereof thatcan be used include diphtheria A chain, nonbinding active fragments ofdiphtheria toxin, exotoxin A chain (from Pseudomonas aeruginosa), ricinA chain, abrin A chain, modeccin A chain, alpha-sarcin, Aleurites fordiiproteins, dianthin proteins, Phytolaca americana proteins (PAPI, PAPII,and PAP-S), momordica charantia inhibitor, curcin, crotin, sapaonariaofficinalis inhibitor, gelonin, mitogellin, restrictocin, phenomycin,enomycin, and the tricothecenes. See, e.g., WO 93/21232 published Oct.28, 1993. A variety of radionuclides are available for the production ofradioconjugated antibodies. Examples include ²¹²Bi, ¹³¹I, ¹³¹In, ⁹⁰Y,and ¹⁸⁶Re. Conjugates of the antibody and cytotoxic agent are made usinga variety of bifunctional protein-coupling agents such asN-succinimidyl-3-(2-pyridyldithiol) propionate (SPDP), iminothiolane(IT), bifunctional derivatives of imidoesters (such as dimethyladipimidate HCl), active esters (such as disuccinimidyl suberate),aldehydes (such as glutaraldehyde), bis-azido compounds (such asbis(p-azidobenzoyl) hexanediamine), bis-diazonium derivatives (such asbis-(p-diazoniumbenzoyl)-ethylenediamine), diisocyanates (such astoluene 2,6-diisocyanate), and bis-active fluorine compounds (such as1,5-difluoro-2,4-dinitrobenzene). For example, a ricin immunotoxin maybe prepared as described in Vitetta et al., Science, 238: 1098 (1987).Carbon-14-labeled 1-isothiocyanatobenzyl-3-methyldiethylenetriaminepentaacetic acid (MX-DTPA) is an exemplary chelating agent forconjugation of radionucleotide to the antibody. See WO94/11026.

Conjugates of an antibody and one or more small molecule toxins, such asa calicheamicin, maytansinoids, dolastatins, aurostatins, atrichothecene, and CC1065, and the derivatives of these toxins that havetoxin activity, are also contemplated herein.

a. Maytansine and Maytansinoids

In some embodiments, the immunoconjugate comprises a humanized antibody(full length or fragments) comprising an ultralong CDR3 as disclosedherein conjugated to one or more maytansinoid molecules.

Maytansinoids are mitototic inhibitors which act by inhibiting tubulinpolymerization. Maytansine was first isolated from the east Africanshrub Maytenus serrata (U.S. Pat. No. 3,896,111). Subsequently, it wasdiscovered that certain microbes also produce maytansinoids, such asmaytansinol and C-3 maytansinol esters (U.S. Pat. No. 4,151,042).Synthetic maytansinol and derivatives and analogues thereof aredisclosed, for example, in U.S. Pat. Nos. 4,137,230; 4,248,870;4,256,746; 4,260,608; 4,265,814; 4,294,757; 4,307,016; 4,308,268;4,308,269; 4,309,428; 4,313,946; 4,315,929; 4,317,821; 4,322,348;4,331,598; 4,361,650; 4,364,866; 4,424,219; 4,450,254; 4,362,663; and4,371,533.

Maytansinoid drug moieties are attractive drug moieties in antibody drugconjugates because they are: (i) relatively accessible to prepare byfermentation or chemical modification, derivatization of fermentationproducts, (ii) amenable to derivatization with functional groupssuitable for conjugation through the non-disulfide linkers toantibodies, (iii) stable in plasma, and (iv) effective against a varietyof tumor cell lines.

Immunoconjugates containing maytansinoids, methods of making same, andtheir therapeutic use are disclosed, for example, in U.S. Pat. Nos.5,208,020, 5,416,064 and EP 0 425 235. Liu et al., Proc. Natl. Acad.Sci. USA 93:8618-8623 (1996) described immunoconjugates comprising amaytansinoid designated DM1 linked to the monoclonal antibody C242directed against human colorectal cancer. The conjugate was found to behighly cytotoxic towards cultured colon cancer cells, and showedantitumor activity in an in vivo tumor growth assay. Chari et al.,Cancer Research 52:127-131 (1992) describe immunoconjugates in which amaytansinoid was conjugated via a disulfide linker to the murineantibody A7 binding to an antigen on human colon cancer cell lines, orto another murine monoclonal antibody TA.1 that binds the HER-2/neuoncogene. The cytotoxicity of the TA.1-maytansinoid conjugate was testedin vitro on the human breast cancer cell line SK-BR-3, which expresses3×10⁵ HER-2 surface antigens per cell. The drug conjugate achieved adegree of cytotoxicity similar to the free maytansinoid drug, whichcould be increased by increasing the number of maytansinoid moleculesper antibody molecule. The A7-maytansinoid conjugate showed low systemiccytotoxicity in mice.

Antibody-maytansinoid conjugates are prepared by chemically linking anantibody to a maytansinoid molecule without significantly diminishingthe biological activity of either the antibody or the maytansinoidmolecule. See, e.g., U.S. Pat. No. 5,208,020. An average of 3-4maytansinoid molecules conjugated per antibody molecule has shownefficacy in enhancing cytotoxicity of target cells without negativelyaffecting the function or solubility of the antibody, although even onemolecule of toxin/antibody would be expected to enhance cytotoxicityover the use of naked antibody. Maytansinoids are well known in the artand can be synthesized by known techniques or isolated from naturalsources. Suitable maytansinoids are disclosed, for example, in U.S. Pat.No. 5,208,020 and in the other patents and nonpatent publicationsreferred to hereinabove. Preferred maytansinoids are maytansinol andmaytansinol analogues modified in the aromatic ring or at otherpositions of the maytansinol molecule, such as various maytansinolesters.

There are many linking groups known in the art for makingantibody-maytansinoid conjugates, including, for example, thosedisclosed in U.S. Pat. Nos. 5,208,020, 6,441,163, or EP Patent 0 425235, Chari et al., Cancer Research 52:127-131 (1992).Antibody-maytansinoid conjugates comprising the linker component SMCCmay be prepared. The linking groups include disulfide groups, thioethergroups, acid labile groups, photolabile groups, peptidase labile groups,or esterase labile groups, as disclosed in the above-identified patents,disulfide and thioether groups being preferred. Additional linkinggroups are described and exemplified herein.

Conjugates of the antibody and maytansinoid may be made using a varietyof bifunctional protein coupling agents such asN-succinimidyl-3-(2-pyridyldithio) propionate (SPDP),succinimidyl-4-(N-maleimidomethyl)cyclohexane-1-carboxylate (SMCC),iminothiolane (IT), bifunctional derivatives of imidoesters (such asdimethyl adipimidate HCl), active esters (such as disuccinimidylsuberate), aldehydes (such as glutaraldehyde), bis-azido compounds (suchas bis(p-azidobenzoyl) hexanediamine), bis-diazonium derivatives (suchas bis-(p-diazoniumbenzoyl)-ethylenediamine), diisocyanates (such astoluene 2,6-diisocyanate), and bis-active fluorine compounds (such as1,5-difluoro-2,4-dinitrobenzene). Particularly preferred coupling agentsinclude N-succinimidyl-3-(2-pyridyldithio)propionate (SPDP) (Carlsson etal., Biochem. J. 173:723-737 (1978)) andN-succinimidyl-4-(2-pyridylthio)pentanoate (SPP) to provide for adisulfide linkage.

The linker may be attached to the maytansinoid molecule at variouspositions, depending on the type of the link. For example, an esterlinkage may be formed by reaction with a hydroxyl group usingconventional coupling techniques. The reaction may occur at the C-3position having a hydroxyl group, the C-14 position modified withhydroxymethyl, the C-15 position modified with a hydroxyl group, and theC-20 position having a hydroxyl group. In a preferred embodiment, thelinkage is formed at the C-3 position of maytansinol or a maytansinolanalogue.

b. Auristatins and Dolastatins

In some embodiments, the immunoconjugate comprises an antibody disclosedherein conjugated to dolastatins or dolostatin peptidic analogs andderivatives, the auristatins (U.S. Pat. Nos. 5,635,483; 5,780,588).Dolastatins and auristatins have been shown to interfere withmicrotubule dynamics, GTP hydrolysis, and nuclear and cellular division(Woyke et al (2001) Antimicrob. Agents and Chemother. 45(12):3580-3584)and have anticancer (U.S. Pat. No. 5,663,149) and antifungal activity(Pettit et al (1998) Antimicrob. Agents Chemother. 42:2961-2965). Thedolastatin or auristatin drug moiety may be attached to the antibodythrough the N (amino) terminus or the C (carboxyl) terminus of thepeptidic drug moiety (WO 02/088172).

Exemplary auristatin embodiments include the N-terminus linkedmonomethylauristatin drug moieties DE and DF, (see, e.g., U.S. Pat. No.7,498,298).

Typically, peptide-based drug moieties can be prepared by forming apeptide bond between two or more amino acids and/or peptide fragments.Such peptide bonds can be prepared, for example, according to the liquidphase synthesis method (see, e.g., E. Schroder and K. Lubke, “ThePeptides”, volume 1, pp 76-136, 1965, Academic Press) that is well knownin the field of peptide chemistry. The auristatin/dolastatin drugmoieties may be prepared according to the methods of: U.S. Pat. No.5,635,483; U.S. Pat. No. 5,780,588; Pettit et al (1989) J. Am. Chem.Soc. 111:5463-5465; Pettit et al. (1998) Anti-Cancer Drug Design13:243-277; Pettit, G. R., et al. Synthesis, 1996, 719-725; and Pettitet al. (1996) J. Chem. Soc. Perkin Trans. 1 5:859-863. See also Doronina(2003) Nat Biotechnol 21(7):778-784; U.S. Pat. No. 7,498,289,(disclosing, linkers and methods of preparing monomethylvaline compoundssuch as MMAE and MMAF conjugated to linkers).

c. Calicheamicin

In other embodiments, the immunoconjugate comprises an antibodydisclosed herein conjugated to one or more calicheamicin molecules. Thecalicheamicin family of antibiotics are capable of producingdouble-stranded DNA breaks at sub-picomolar concentrations. For thepreparation of conjugates of the calicheamicin family, see U.S. Pat.Nos. 5,712,374, 5,714,586, 5,739,116, 5,767,285, 5,770,701, 5,770,710,5,773,001, 5,877,296. Structural analogues of calicheamicin which may beused include, but are not limited to, γ₁ ^(l), α₂ ^(l), α₃ ^(l),N-acetyl-γ₁ ^(l), PSAG and θ^(l) ₁ (see, e.g., Hinman et al., CancerResearch 53:3336-3342 (1993), Lode et al., Cancer Research 58:2925-2928(1998) and the aforementioned U.S. patents). Another anti-tumor drugthat the antibody can be conjugated is QFA which is an antifolate. Bothcalicheamicin and QFA have intracellular sites of action and do notreadily cross the plasma membrane. Therefore, cellular uptake of theseagents through antibody mediated internalization greatly enhances theircytotoxic effects.

d. Other Cytotoxic Agents

Other antitumor agents that can be conjugated to the antibodiesdisclosed herein include BCNU, streptozoicin, vincristine and5-fluorouracil, the family of agents known collectively LL-E33288complex described in U.S. Pat. Nos. 5,053,394, 5,770,710, as well asesperamicins (U.S. Pat. No. 5,877,296).

Enzymatically active toxins and fragments thereof which can be usedinclude diphtheria A chain, nonbinding active fragments of diphtheriatoxin, exotoxin A chain (from Pseudomonas aeruginosa), ricin A chain,abrin A chain, modeccin A chain, alpha-sarcin, Aleurites fordiiproteins, dianthin proteins, Phytolaca americana proteins (PAPI, PAPII,and PAP-S), momordica charantia inhibitor, curcin, crotin, sapaonariaofficinalis inhibitor, gelonin, mitogellin, restrictocin, phenomycin,enomycin and the tricothecenes. See, for example, WO 93/21232 publishedOct. 28, 1993.

The present disclosure further contemplates an immunoconjugate formedbetween an antibody and a compound with nucleolytic activity (e.g., aribonuclease or a DNA endonuclease such as a deoxyribonuclease; DNase).

For selective destruction of the tumor, the antibody may comprise ahighly radioactive atom. A variety of radioactive isotopes are availablefor the production of radioconjugated antibodies. Examples includeAt²¹¹, I¹³¹, I¹²⁵, Y⁹⁰, Re¹⁸⁶, Re¹⁸⁸, Sm¹⁵³, Bi²¹², P³², Pb²¹² andradioactive isotopes of Lu. When the conjugate is used for detection, itmay comprise a radioactive atom for scintigraphic studies, for exampletc^(99m) or I¹²³, or a spin label for nuclear magnetic resonance (NMR)imaging (also known as magnetic resonance imaging, mri), such asiodine-123 again, iodine-131, indium-111, fluorine-19, carbon-13,nitrogen-15, oxygen-17, gadolinium, manganese or iron.

The radiolabels or other labels may be incorporated in the conjugate inknown ways. For example, the peptide may be biosynthesized or may besynthesized by chemical amino acid synthesis using suitable amino acidprecursors involving, for example, fluorine-19 in place of hydrogen.Labels such as tc^(99m) or I¹²³, Re¹⁸⁶, Re¹⁸⁸ and In¹¹¹ can be attachedvia a cysteine residue in the peptide. Yttrium-90 can be attached via alysine residue. The IODOGEN method (Fraker et al (1978) Biochem.Biophys. Res. Commun. 80: 49-57) can be used to incorporate iodine-123.“Monoclonal Antibodies in Immunoscintigraphy” (Chatal, CRC Press 1989)describes other methods.

Conjugates of the antibody and cytotoxic agent may be made using avariety of bifunctional protein coupling agents such asN-succinimidyl-3-(2-pyridyldithio) propionate (SPDP),succinimidyl-4-(N-maleimidomethyl)cyclohexane-1-carboxylate (SMCC),iminothiolane (IT), bifunctional derivatives of imidoesters (such asdimethyl adipimidate HCl), active esters (such as disuccinimidylsuberate), aldehydes (such as glutaraldehyde), bis-azido compounds (suchas bis(p-azidobenzoyl) hexanediamine), bis-diazonium derivatives (suchas bis-(p-diazoniumbenzoyl)-ethylenediamine), diisocyanates (such astoluene 2,6-diisocyanate), and bis-active fluorine compounds (such as1,5-difluoro-2,4-dinitrobenzene). For example, a ricin immunotoxin canbe prepared as described in Vitetta et al., Science 238:1098 (1987).Carbon-14-labeled 1-isothiocyanatobenzyl-3-methyldiethylenetriaminepentaacetic acid (MX-DTPA) is an exemplary chelating agent forconjugation of radionucleotide to the antibody. See WO94/11026. Thelinker may be a “cleavable linker” facilitating release of the cytotoxicdrug in the cell. For example, an acid-labile linker,peptidase-sensitive linker, photolabile linker, dimethyl linker ordisulfide-containing linker (Chari et al., Cancer Research 52:127-131(1992); U.S. Pat. No. 5,208,020) may be used.

The compounds disclosed herein expressly contemplate, but are notlimited to, ADC prepared with cross-linker reagents: BMPS, EMCS, GMBS,HBVS, LC-SMCC, MBS, MPBH, SBAP, SIA, SIAB, SMCC, SMPB, SMPH, sulfo-EMCS,sulfo-GMBS, sulfo-KMUS, sulfo-MBS, sulfo-SIAB, sulfo-SMCC, andsulfo-SMPB, and SVSB (succinimidyl-(4-vinylsulfone)benzoate) which arecommercially available (e.g., from Pierce Biotechnology, Inc., Rockford,Ill., U.S.A). See pages 467-498, 2003-2004 Applications Handbook andCatalog.

e. Preparation of Antibody Drug Conjugates

In the antibody drug conjugates (ADC) disclosed herein, an antibody (Ab)is conjugated to one or more drug moieties (D), e.g., about 1 to about20 drug moieties per antibody, through a linker (L). An ADC of Formula I[Ab-(L-D)_(p)] may be prepared by several routes, employing organicchemistry reactions, conditions, and reagents known to those skilled inthe art, including: (1) reaction of a nucleophilic group of an antibodywith a bivalent linker reagent, to form Ab-L, via a covalent bond,followed by reaction with a drug moiety D; and (2) reaction of anucleophilic group of a drug moiety with a bivalent linker reagent, toform D-L, via a covalent bond, followed by reaction with thenucleophilic group of an antibody. Additional methods for preparing ADCare described herein.

The linker may be composed of one or more linker components. Exemplarylinker components include 6-maleimidocaproyl (“MC”), maleimidopropanoyl(“MP”), valine-citrulline (“val-cit”), alanine-phenylalanine(“ala-phe”), p-aminobenzyloxycarbonyl (“PAB”), N-Succinimidyl4-(2-pyridylthio)pentanoate (“SPP”), N-Succinimidyl4-(N-maleimidomethyl)cyclohexane-1 carboxylate (“SMCC”), andN-Succinimidyl (4-iodo-acetyl)aminobenzoate (“SIAB”). Additional linkercomponents are known in the art and some are disclosed herein (see,e.g., U.S. Pat. No. 7,498,298).

In some embodiments, the linker may comprise amino acid residues.Exemplary amino acid linker components include a dipeptide, atripeptide, a tetrapeptide or a pentapeptide. Exemplary dipeptidesinclude: valine-citrulline (vc or val-cit), alanine-phenylalanine (af orala-phe). Exemplary tripeptides include: glycine-valine-citrulline(gly-val-cit) and glycine-glycine-glycine (gly-gly-gly). Amino acidresidues which comprise an amino acid linker component include thoseoccurring naturally, as well as minor amino acids and non-naturallyoccurring amino acid analogs, such as citrulline. Amino acid linkercomponents can be designed and optimized in their selectivity forenzymatic cleavage by a particular enzymes, for example, atumor-associated protease, cathepsin B, C and D, or a plasmin protease.

Nucleophilic groups on antibodies include, but are not limited to: (i)N-terminal amine groups, (ii) side chain amine groups, e.g., lysine,(iii) side chain thiol groups, e.g., cysteine, and (iv) sugar hydroxylor amino groups where the antibody is glycosylated. Amine, thiol, andhydroxyl groups are nucleophilic and capable of reacting to formcovalent bonds with electrophilic groups on linker moieties and linkerreagents including: (i) active esters such as NHS esters, HOBt esters,haloformates, and acid halides; (ii) alkyl and benzyl halides such ashaloacetamides; (iii) aldehydes, ketones, carboxyl, and maleimidegroups. Certain antibodies have reducible interchain disulfides, e.g.,cysteine bridges. Antibodies may be made reactive for conjugation withlinker reagents by treatment with a reducing agent such as DTT(dithiothreitol). Each cysteine bridge will thus form, theoretically,two reactive thiol nucleophiles. Additional nucleophilic groups can beintroduced into antibodies through the reaction of lysines with2-iminothiolane (Traut's reagent) resulting in conversion of an amineinto a thiol. Reactive thiol groups may be introduced into the antibody(or fragment thereof) by introducing one, two, three, four, or morecysteine residues (e.g., preparing mutant antibodies comprising one ormore non-native cysteine amino acid residues).

Antibody drug conjugates disclosed herein may also be produced bymodification of the antibody to introduce electrophilic moieties, whichcan react with nucleophilic substituents on the linker reagent or drug.The sugars of glycosylated antibodies may be oxidized, e.g., withperiodate oxidizing reagents, to form aldehyde or ketone groups whichmay react with the amine group of linker reagents or drug moieties. Theresulting imine Schiff base groups may form a stable linkage, or may bereduced, e.g., by borohydride reagents to form stable amine linkages. Inone embodiment, reaction of the carbohydrate portion of a glycosylatedantibody with either galactose oxidase or sodium meta-periodate mayyield carbonyl (aldehyde and ketone) groups in the protein that canreact with appropriate groups on the drug (Hermanson, BioconjugateTechniques). In another embodiment, proteins containing N-terminalserine or threonine residues can react with sodium meta-periodate,resulting in production of an aldehyde in place of the first amino acid(Geoghegan & Stroh, (1992) Bioconjugate Chem. 3:138-146; U.S. Pat. No.5,362,852). Such aldehyde can be reacted with a drug moiety or linkernucleophile.

Likewise, nucleophilic groups on a drug moiety include, but are notlimited to: amine, thiol, hydroxyl, hydrazide, oxime, hydrazine,thiosemicarbazone, hydrazine carboxylate, and arylhydrazide groupscapable of reacting to form covalent bonds with electrophilic groups onlinker moieties and linker reagents including: (i) active esters such asNHS esters, HOBt esters, haloformates, and acid halides; (ii) alkyl andbenzyl halides such as haloacetamides; (iii) aldehydes, ketones,carboxyl, and maleimide groups.

Alternatively, a fusion protein comprising the antibody and cytotoxicagent may be made, e.g., by recombinant techniques or peptide synthesis.The length of DNA may comprise respective regions encoding the twoportions of the conjugate either adjacent one another or separated by aregion encoding a linker peptide which does not destroy the desiredproperties of the conjugate.

In yet another embodiment, the antibody may be conjugated to a“receptor” (such streptavidin) for utilization in tumor pre-targetingwherein the antibody-receptor conjugate is administered to the patient,followed by removal of unbound conjugate from the circulation using aclearing agent and then administration of a “ligand” (e.g., avidin)which is conjugated to a cytotoxic agent (e.g., a radionucleotide).

Engineered Hybridomas

Hybridoma cells can be generated by fusing B cells producing a desiredantibody with an immortalized cell line, usually a myeloma cell line, sothat the resulting fusion cells will be an immortalized cell line thatsecrets a particular antibody. By the same principle, myeloma cells canbe first transfected with a nucleic acid encoding a germline antibody Vregion and can be screened for the expression of the germline V region.Those myeloma cells with highest level of proteolytic light chainexpression can be subsequently fused with B cells that produce anantibody with desired target protein specificity. The fusion cells willproduce two types of antibodies: one is a heterologous antibodycontaining an endogenous antibody chain (either heavy or light) operablyjoined to the recombinant germline V region (either heavy or light), andthe other is the same antibody that the parental B cells would secrete(e.g. both endogenous heavy and light chains). The operably joinedheterologous heavy and light chains can be isolated by conventionalmethods such as chromatography and identification can be confirmed bytarget protein binding assays, assays identifying a unique tag of thegermline polypeptide, or endopeptidase activity assays described inother sections of this disclosure. In some cases, where the heterologousantibody is the predominant type in quantity among the two types ofantibodies, such isolation may not be needed. Hybridomas. Includingbovine hybridomas, may be a source of bovine antibody gene sequences,including ultralong CDR3 sequences.

Transgenic Mammals

A nucleic acid sequence encoding a germline antibody polypeptide of thepresent disclosure can be introduced into a non-human mammal to generatea transgenic animal that expresses the germline antibody polypeptide.Unlike the transgenic animal models more commonly seen, the transgeneexpressed by the transgenic mammals of the present disclosure need notreplace at least one allele of the endogenous coding sequenceresponsible for the variable regions of antibody chains followingsomatic recombination. Due to allelic exclusion, the presence of anexogenous, post-somatic rearrangement version of the germline V regionDNA will inhibit the endogenous alleles of pre-somatic rearrangement Vminigenes from undergoing somatic rearrangement and contributing to themakeup of antibody chains this mammal may produce. Thus, when exposed toa particular antigen, the mammal will generate heterologous antibodiescomprising one endogenously rearranged antibody chain, and onetransgenic gene which was rearranged a priori. Such heterologousantibodies are invaluable in research and in treating certain conditionsin live subjects. On the other hand, a method that directs theintegration of the transgene to the locus of an endogenous allele willfully serve the purpose of practicing the present disclosure as well.

The general methods of generating transgenic animals have been wellestablished and frequently practiced. For reviews and protocols forgenerating transgenic animals and related methods for geneticmanipulations, see, e.g., Mansour et al., Nature 336:348-352 (1988);Capecchi et al., Trends Genet. 5:70-76 (1989); Capecchi, Science244:1288-1292 (1989); Capecchi et al., Current Communications inMolecular Biology, pp 45-52, Capecchi, M. R. (ed.), Cold Spring HarborPress, Cold Spring Harbor, N.Y. (1989); Frohman et al., Cell 56: 145-147(1989); Brinster et al., Proc. Natl. Acad. Sci. USA 82:4438-4442 (1985);Evans et. al., Nature 292:154-156 (1981); Bradley et al., Nature309:255-258 (1984); Gossler et al., Proc. Natl. Acad. Sci. USA83:9065-9069 (1986); Robertson et al., Nature 322:445-448 (1986);Jaenisch Science 240:1468-1474 (1988); and Siedel, G. E., Jr., “Criticalreview of embryo transfer procedures with cattle” in Fertilization andEmbryonic Development in Vitro, page 323, L. Mastroianni, Jr. and J. D.Biggers, ed., Plenum Press, New York, N.Y. (1981).

An exemplary transgenic animal of the present disclosure is mouse,whereas a number of other transgenic animals can also be produced usingthe same general method. These animals include, but are not limited to:rabbits, sheep, cattle, and pigs (Jaenisch Science 240:1468-1474 (1988);Hammer et al., J. Animal. Sci. 63:269 (1986); Hammer et al. Nature315:680 (1985); Wagner et al., Theriogenology 21:29 (1984)).

Pharmaceutical Compositions

Humanized antibodies comprising an ultralong CDR3, antibody fragments,nucleic acids, or vectors disclosed herein can be formulated incompositions, especially pharmaceutical compositions. Such compositionswith humanized antibodies comprising an ultralong CDR3 comprise atherapeutically or prophylactically effective amount of a humanizedantibodies comprising an ultralong CDR3, antibody fragment, nucleicacid, or vector disclosed herein in admixture with a suitable carrier,e.g., a pharmaceutically acceptable agent. Typically, humanizedantibodies comprising an ultralong CDR3, antibody fragments, nucleicacids, or vectors disclosed herein are sufficiently purified foradministration before formulation in a pharmaceutical composition.

Pharmaceutically acceptable agents for use in the present pharmaceuticalcompositions include carriers, excipients, diluents, antioxidants,preservatives, coloring, flavoring and diluting agents, emulsifyingagents, suspending agents, solvents, fillers, bulking agents, buffers,delivery vehicles, tonicity agents, cosolvents, wetting agents,complexing agents, buffering agents, antimicrobials, and surfactants.

Neutral buffered saline or saline mixed with serum albumin are exemplaryappropriate carriers. The pharmaceutical compositions may includeantioxidants such as ascorbic acid; low molecular weight polypeptides;proteins, such as serum albumin, gelatin, or immunoglobulins;hydrophilic polymers such as polyvinylpyrrolidone; amino acids such asglycine, glutamine, asparagine, arginine or lysine; monosaccharides,disaccharides, and other carbohydrates including glucose, mannose, ordextrins; chelating agents such as EDTA; sugar alcohols such as mannitolor sorbitol; salt-forming counterions such as sodium; and/or nonionicsurfactants such as Tween, pluronics, or polyethylene glycol (PEG). Alsoby way of example, suitable tonicity enhancing agents include alkalimetal halides (preferably sodium or potassium chloride), mannitol,sorbitol, and the like. Suitable preservatives include benzalkoniumchloride, thimerosal, phenethyl alcohol, methylparaben, propylparaben,chlorhexidine, sorbic acid and the like. Hydrogen peroxide also may beused as preservative. Suitable cosolvents include glycerin, propyleneglycol, and PEG. Suitable complexing agents include caffeine,polyvinylpyrrolidone, beta-cyclodextrin orhydroxy-propyl-beta-cyclodextrin. Suitable surfactants or wetting agentsinclude sorbitan esters, polysorbates such as polysorbate 80,tromethamine, lecithin, cholesterol, tyloxapal, and the like. Thebuffers may be conventional buffers such as acetate, borate, citrate,phosphate, bicarbonate, or Tris-HCl. Acetate buffer may be about pH4-5.5, and Tris buffer can be about pH 7-8.5. Additional pharmaceuticalagents are set forth in Remington's Pharmaceutical Sciences, 18thEdition, A. R. Gennaro, ed., Mack Publishing Company, 1990.

The composition may be in liquid form or in a lyophilized orfreeze-dried form and may include one or more lyoprotectants,excipients, surfactants, high molecular weight structural additivesand/or bulking agents (see, for example, U.S. Pat. Nos. 6,685,940,6,566,329, and 6,372,716). In one embodiment, a lyoprotectant isincluded, which is a non-reducing sugar such as sucrose, lactose ortrehalose. The amount of lyoprotectant generally included is such that,upon reconstitution, the resulting formulation will be isotonic,although hypertonic or slightly hypotonic formulations also may besuitable. In addition, the amount of lyoprotectant should be sufficientto prevent an unacceptable amount of degradation and/or aggregation ofthe protein upon lyophilization. Exemplary lyoprotectant concentrationsfor sugars (e.g., sucrose, lactose, trehalose) in the pre-lyophilizedformulation are from about 10 mM to about 400 mM. In another embodiment,a surfactant is included, such as for example, nonionic surfactants andionic surfactants such as polysorbates (e.g., polysorbate 20,polysorbate 80); poloxamers (e.g., poloxamer 188); poly(ethylene glycol)phenyl ethers (e.g., Triton); sodium dodecyl sulfate (SDS); sodiumlaurel sulfate; sodium octyl glycoside; lauryl-, myristyl-, linoleyl-,or stearyl-sulfobetaine; lauryl-, myristyl-, linoleyl- orstearyl-sarcosine; linoleyl, myristyl-, or cetyl-betaine;lauroamidopropyl-, cocamidopropyl-, linoleamidopropyl-,myristamidopropyl-, palmidopropyl-, or isostearamidopropyl-betaine(e.g., lauroamidopropyl); myristamidopropyl-, palmidopropyl-, orisostearamidopropyl-dimethylamine; sodium methyl cocoyl-, or disodiummethyl oleyl-taurate; and the MONAQUAT™. series (Mona Industries, Inc.,Paterson, N.J.), polyethyl glycol, polypropyl glycol, and copolymers ofethylene and propylene glycol (e.g., Pluronics, PF68 etc). Exemplaryamounts of surfactant that may be present in the pre-lyophilizedformulation are from about 0.001-0.5%. High molecular weight structuraladditives (e.g., fillers, binders) may include for example, acacia,albumin, alginic acid, calcium phosphate (dibasic), cellulose,carboxymethylcellulose, carboxymethylcellulose sodium,hydroxyethylcellulose, hydroxypropylcellulose,hydroxypropylmethylcellulose, microcrystalline cellulose, dextran,dextrin, dextrates, sucrose, tylose, pregelatinized starch, calciumsulfate, amylose, glycine, bentonite, maltose, sorbitol, ethylcellulose,disodium hydrogen phosphate, disodium phosphate, disodium pyrosulfite,polyvinyl alcohol, gelatin, glucose, guar gum, liquid glucose,compressible sugar, magnesium aluminum silicate, maltodextrin,polyethylene oxide, polymethacrylates, povidone, sodium alginate,tragacanth microcrystalline cellulose, starch, and zein. Exemplaryconcentrations of high molecular weight structural additives are from0.1% to 10% by weight. In other embodiments, a bulking agent (e.g.,mannitol, glycine) may be included.

Compositions may be suitable for parenteral administration. Exemplarycompositions are suitable for injection or infusion into an animal byany route available to the skilled worker, such as intraarticular,subcutaneous, intravenous, intramuscular, intraperitoneal, intracerebral(intraparenchymal), intracerebroventricular, intramuscular, intraocular,intraarterial, or intralesional routes. A parenteral formulationtypically will be a sterile, pyrogen-free, isotonic aqueous solution,optionally containing pharmaceutically acceptable preservatives.

Examples of non-aqueous solvents are propylene glycol, polyethyleneglycol, vegetable oils such as olive oil, and injectable organic esterssuch as ethyl oleate. Aqueous carriers include water, alcoholic/aqueoussolutions, emulsions or suspensions, including saline and bufferedmedia. Parenteral vehicles include sodium chloride solution, Ringers'dextrose, dextrose and sodium chloride, lactated Ringer's, or fixedoils. Intravenous vehicles include fluid and nutrient replenishers,electrolyte replenishers, such as those based on Ringer's dextrose, andthe like. Preservatives and other additives may also be present, suchas, for example, anti-microbials, anti-oxidants, chelating agents, inertgases and the like. See generally, Remington's Pharmaceutical Science,16th Ed., Mack Eds., 1980.

Pharmaceutical compositions described herein may be formulated forcontrolled or sustained delivery in a manner that provides localconcentration of the product (e.g., bolus, depot effect) and/orincreased stability or half-life in a particular local environment. Thecompositions can include the formulation of humanized antibodiescomprising an ultralong CDR3, antibody fragments, nucleic acids, orvectors disclosed herein with particulate preparations of polymericcompounds such as polylactic acid, polyglycolic acid, etc., as well asagents such as a biodegradable matrix, injectable microspheres,microcapsular particles, microcapsules, bioerodible particles beads,liposomes, and implantable delivery devices that provide for thecontrolled or sustained release of the active agent which then can bedelivered as a depot injection. Techniques for formulating suchsustained- or controlled-delivery means are known and a variety ofpolymers have been developed and used for the controlled release anddelivery of drugs. Such polymers are typically biodegradable andbiocompatible. Polymer hydrogels, including those formed by complexationof enantiomeric polymer or polypeptide segments, and hydrogels withtemperature or pH sensitive properties, may be desirable for providingdrug depot effect because of the mild and aqueous conditions involved intrapping bioactive protein agents (e.g., humanized antibodies comprisingan ultralong CDR3). See, for example, the description of controlledrelease porous polymeric microparticles for the delivery ofpharmaceutical compositions in WO 93/15722.

Suitable materials for this purpose include polylactides (see, e.g.,U.S. Pat. No. 3,773,919), polymers of poly-(a-hydroxycarboxylic acids),such as poly-D-(−)-3-hydroxybutyric acid (EP 133,988A), copolymers ofL-glutamic acid and gamma ethyl-L-glutamate (Sidman et al., Biopolymers,22: 547-556 (1983)), poly(2-hydroxyethyl-methacrylate) (Langer et al.,J. Biomed. Mater. Res., 15: 167-277 (1981), and Langer, Chem. Tech., 12:98-105 (1982)), ethylene vinyl acetate, or poly-D(−)-3-hydroxybutyricacid. Other biodegradable polymers include poly(lactones),poly(acetals), poly(orthoesters), and poly(orthocarbonates).Sustained-release compositions also may include liposomes, which can beprepared by any of several methods known in the art (see, e.g., Eppsteinet al., Proc. Natl. Acad. Sci. USA, 82: 3688-92 (1985)). The carrieritself, or its degradation products, should be nontoxic in the targettissue and should not further aggravate the condition. This can bedetermined by routine screening in animal models of the target disorderor, if such models are unavailable, in normal animals.

Microencapsulation of recombinant proteins for sustained release hasbeen performed successfully with human growth hormone (rhGH),interferon-(rhIFN-), interleukin-2, and MN rgp120. Johnson et al., Nat.Med., 2:795-799 (1996); Yasuda, Biomed. Ther., 27:1221-1223 (1993); Horaet al., Bio/Technology. 8:755-758 (1990); Cleland, “Design andProduction of Single Immunization Vaccines Using PolylactidePolyglycolide Microsphere Systems,” in Vaccine Design: The Subunit andAdjuvant Approach, Powell and Newman, eds, (Plenum Press: New York,1995), pp. 439-462; WO 97/03692, WO 96/40072, WO 96/07399; and U.S. Pat.No. 5,654,010. The sustained-release formulations of these proteins weredeveloped using poly-lactic-coglycolic acid (PLGA) polymer due to itsbiocompatibility and wide range of biodegradable properties. Thedegradation products of PLGA, lactic and glycolic acids can be clearedquickly within the human body. Moreover, the degradability of thispolymer can be depending on its molecular weight and composition. Lewis,“Controlled release of bioactive agents from lactide/glycolide polymer,”in: M. Chasin and R. Langer (Eds.), Biodegradable Polymers as DrugDelivery Systems (Marcel Dekker: New York, 1990), pp. 1-41. Additionalexamples of sustained release compositions include, for example, EP58,481A, U.S. Pat. No. 3,887,699, EP 158,277A, Canadian Patent No.1176565, U. Sidman et al., Biopolymers 22, 547 [1983], R. Langer et al.,Chem. Tech. 12, 98 [1982], Sinha et al., J. Control. Release 90, 261[2003], Zhu et al., Nat. Biotechnol. 18, 24 [2000], and Dai et al.,Colloids Surf B Biointerfaces 41, 117 [2005].

Bioadhesive polymers are also contemplated for use in or withcompositions of the present disclosure. Bioadhesives are synthetic andnaturally occurring materials able to adhere to biological substratesfor extended time periods. For example, Carbopol and polycarbophil areboth synthetic cross-linked derivatives of poly(acrylic acid).Bioadhesive delivery systems based on naturally occurring substancesinclude for example hyaluronic acid, also known as hyaluronan.Hyaluronic acid is a naturally occurring mucopolysaccharide consistingof residues of D-glucuronic and N-acetyl-D-glucosamine. Hyaluronic acidis found in the extracellular tissue matrix of vertebrates, including inconnective tissues, as well as in synovial fluid and in the vitreous andaqueous humor of the eye. Esterified derivatives of hyaluronic acid havebeen used to produce microspheres for use in delivery that arebiocompatible and biodegradable (see, for example, Cortivo et al.,Biomaterials (1991) 12:727-730; EP 517,565; WO 96/29998; Illum et al.,J. Controlled Rel. (1994) 29:133-141). Exemplary hyaluronic acidcontaining compositions of the present disclosure comprise a hyaluronicacid ester polymer in an amount of approximately 0.1% to about 40% (w/w)of a humanized antibody comprising an ultralong CDR3 to hyaluronic acidpolymer.

Both biodegradable and non-biodegradable polymeric matrices may be usedto deliver compositions of the present disclosure, and such polymericmatrices may comprise natural or synthetic polymers. Biodegradablematrices are preferred. The period of time over which release occurs isbased on selection of the polymer. Typically, release over a periodranging from between a few hours and three to twelve months is mostdesirable. Exemplary synthetic polymers which may be used to form thebiodegradable delivery system include: polymers of lactic acid andglycolic acid, polyamides, polycarbonates, polyalkylenes, polyalkyleneglycols, polyalkylene oxides, polyalkylene terepthalates, polyvinylalcohols, polyvinyl ethers, polyvinyl esters, poly-vinyl halides,polyvinylpyrrolidone, polyglycolides, polysiloxanes, polyanhydrides,polyurethanes and co-polymers thereof, poly(butic acid), poly(valericacid), alkyl cellulose, hydroxyalkyl celluloses, cellulose ethers,cellulose esters, nitro celluloses, polymers of acrylic and methacrylicesters, methyl cellulose, ethyl cellulose, hydroxypropyl cellulose,hydroxypropyl methyl cellulose, hydroxybutyl methyl cellulose, celluloseacetate, cellulose propionate, cellulose acetate butyrate, celluloseacetate phthalate, carboxylethyl cellulose, cellulose triacetate,cellulose sulphate sodium salt, poly(methyl methacrylate), poly(ethylmethacrylate), poly(butylmethacrylate), poly(isobutyl methacrylate),poly(hexylmethacrylate), poly(isodecyl methacrylate), poly(laurylmethacrylate), poly(phenyl methacrylate), poly(methyl acrylate),poly(isopropyl acrylate), poly(isobutyl acrylate), poly(octadecylacrylate), polyethylene, polypropylene, poly(ethylene glycol),poly(ethylene oxide), poly(ethylene terephthalate), poly(vinylalcohols), polyvinyl acetate, poly vinyl chloride, polystyrene andpolyvinylpyrrolidone. Exemplary natural polymers include alginate andother polysaccharides including dextran and cellulose, collagen,chemical derivatives thereof (substitutions, additions of chemicalgroups, for example, alkyl, alkylene, hydroxylations, oxidations, andother modifications routinely made by those skilled in the art), albuminand other hydrophilic proteins, zein and other prolamines andhydrophobic proteins, copolymers and mixtures thereof. In general, thesematerials degrade either by enzymatic hydrolysis or exposure to water invivo, by surface or bulk erosion. The polymer optionally is in the formof a hydrogel (see, for example, WO 04/009664, WO 05/087201, Sawhney, etal., Macromolecules, 1993, 26, 581-587) that can absorb up to about 90%of its weight in water and further, optionally is cross-linked withmulti-valent ions or other polymers.

Delivery systems also include non-polymer systems that are lipidsincluding sterols such as cholesterol, cholesterol esters and fattyacids or neutral fats such as mono-di- and tri-glycerides; hydrogelrelease systems; silastic systems; peptide based systems; wax coatings;compressed tablets using conventional binders and excipients; partiallyfused implants; and the like. Specific examples include, but are notlimited to: (a) erosional systems in which the product is contained in aform within a matrix such as those described in U.S. Pat. Nos.4,452,775, 4,675,189 and 5,736,152 and (b) diffusional systems in whicha product permeates at a controlled rate from a polymer such asdescribed in U.S. Pat. Nos. 3,854,480, 5,133,974 and 5,407,686.Liposomes containing the product may be prepared by methods knownmethods, such as for example (DE 3,218,121; Epstein et al., Proc. Natl.Acad. Sci. USA, 82: 3688-3692 (1985); Hwang et al., Proc. Natl. Acad.Sci. USA, 77: 4030-4034 (1980); EP 52,322; EP 36,676; EP 88,046; EP143,949; EP 142,641; JP 83-118008; U.S. Pat. Nos. 4,485,045 and4,544,545; and EP 102,324).

Alternatively or additionally, the compositions may be administeredlocally via implantation into the affected area of a membrane, sponge,or other appropriate material on to which a humanized antibodycomprising an ultralong CDR3, antibody fragment, nucleic acid, or vectordisclosed herein has been absorbed or encapsulated. Where animplantation device is used, the device may be implanted into anysuitable tissue or organ, and delivery of a humanized antibodycomprising an ultralong CDR3 antibody fragment, nucleic acid, or vectordisclosed herein can be directly through the device via bolus, or viacontinuous administration, or via catheter using continuous infusion.

A pharmaceutical composition comprising a humanized antibody comprisingan ultralong CDR3, antibody fragment, nucleic acid, or vector disclosedherein may be formulated for inhalation, such as for example, as a drypowder. Inhalation solutions also may be formulated in a liquefiedpropellant for aerosol delivery. In yet another formulation, solutionsmay be nebulized. Additional pharmaceutical composition for pulmonaryadministration include, those described, for example, in WO 94/20069,which discloses pulmonary delivery of chemically modified proteins. Forpulmonary delivery, the particle size should be suitable for delivery tothe distal lung. For example, the particle size may be from 1 μm to 5μm; however, larger particles may be used, for example, if each particleis fairly porous.

Certain formulations containing humanized antibodies comprising anultralong CDR3, antibody fragments, nucleic acids, or vectors disclosedherein may be administered orally. Formulations administered in thisfashion may be formulated with or without those carriers customarilyused in the compounding of solid dosage forms such as tablets andcapsules. For example, a capsule can be designed to release the activeportion of the formulation at the point in the gastrointestinal tractwhen bioavailability is maximized and pre-systemic degradation isminimized. Additional agents may be included to facilitate absorption ofa selective binding agent. Diluents, flavorings, low melting pointwaxes, vegetable oils, lubricants, suspending agents, tabletdisintegrating agents, and binders also can be employed.

Another preparation may involve an effective quantity of a humanizedantibody comprising an ultralong CDR3, antibody fragment, nucleic acid,or vector disclosed herein in a mixture with non-toxic excipients whichare suitable for the manufacture of tablets. By dissolving the tabletsin sterile water, or another appropriate vehicle, solutions may beprepared in unit dose form. Suitable excipients include, but are notlimited to, inert diluents, such as calcium carbonate, sodium carbonateor bicarbonate, lactose, or calcium phosphate; or binding agents, suchas starch, gelatin, or acacia; or lubricating agents such as magnesiumstearate, stearic acid, or talc.

Suitable and/or preferred pharmaceutical formulations may be determinedin view of the present disclosure and general knowledge of formulationtechnology, depending upon the intended route of administration,delivery format, and desired dosage. Regardless of the manner ofadministration, an effective dose may be calculated according to patientbody weight, body surface area, or organ size. Further refinement of thecalculations for determining the appropriate dosage for treatmentinvolving each of the formulations described herein are routinely madein the art and is within the ambit of tasks routinely performed in theart. Appropriate dosages may be ascertained through use of appropriatedose-response data.

In some embodiments, humanized antibodies comprising an ultralong CDR3or fragments thereof are provided with a modified Fc region where anaturally-occurring Fc region is modified to increase the half-life ofthe antibody or fragment in a biological environment, for example, theserum half-life or a half-life measured by an in vitro assay. Methodsfor altering the original form of a Fc region of an IgG also aredescribed in U.S. Pat. No. 6,998,253.

In certain embodiments, it may be desirable to modify the antibody orfragment in order to increase its serum half-life, for example, addingmolecules such as PEG or other water soluble polymers, includingpolysaccharide polymers, to antibody fragments to increase thehalf-life. This may also be achieved, for example, by incorporation of asalvage receptor binding epitope into the antibody fragment (e.g., bymutation of the appropriate region in the antibody fragment or byincorporating the epitope into a peptide tag that is then fused to theantibody fragment at either end or in the middle, e.g., by DNA orpeptide synthesis) (see, International Publication No. WO96/32478).Salvage receptor binding epitope refers to an epitope of the Fc regionof an IgG molecule (e.g., IgG1, IgG2, IgG3, or IgG4) that is responsiblefor increasing the in vivo serum half-life of the IgG molecule.

A salvage receptor binding epitope may include a region wherein any oneor more amino acid residues from one or two loops of a Fc domain aretransferred to an analogous position of the antibody fragment. Even morepreferably, three or more residues from one or two loops of the Fcdomain are transferred. Still more preferred, the epitope is taken fromthe CH2 domain of the Fc region (e.g., of an IgG) and transferred to theCH1, CH3, or VH region, or more than one such region, of the antibody.Alternatively, the epitope is taken from the CH2 domain of the Fc regionand transferred to the C_(L) region or V_(L) region, or both, of theantibody fragment. See also WO 97/34631 and WO 96/32478 which describeFc variants and their interaction with the salvage receptor.

Mutation of residues within Fc receptor binding sites may result inaltered effector function, such as altered ADCC or CDC activity, oraltered half-life. Potential mutations include insertion, deletion orsubstitution of one or more residues, including substitution withalanine, a conservative substitution, a non-conservative substitution,or replacement with a corresponding amino acid residue at the sameposition from a different IgG subclass (e.g., replacing an IgG1 residuewith a corresponding IgG2 residue at that position). For example, it hasbeen reported that mutating the serine at amino acid position 241 inIgG4 to proline (found at that position in IgG1 and IgG2) led to theproduction of a homogeneous antibody, as well as extending serumhalf-life and improving tissue distribution compared to the originalchimeric IgG4. (Angal et al., Mol. Immunol. 30:105-8, 1993).

Kits/Articles of Manufacture

As an additional aspect, the present disclosure includes kits whichcomprise one or more compounds or compositions packaged in a mannerwhich facilitates their use to practice methods of the presentdisclosure. In one embodiment, such a kit includes a compound orcomposition described herein (e.g., a composition comprising a humanizedantibody comprising an ultralong CDR3 alone or in combination with asecond agent), packaged in a container with a label affixed to thecontainer or a package insert that describes use of the compound orcomposition in practicing the method. Suitable containers include, forexample, bottles, vials, syringes, etc. The containers may be formedfrom a variety of materials such as glass or plastic. The container mayhave a sterile access port (for example the container may be anintravenous solution bag or a vial having a stopper pierceable by ahypodermic injection needle). The article of manufacture may comprise(a) a first container with a composition contained therein, wherein thecomposition comprises a humanized antibody comprising an ultralong CDR3as disclosed herein; and (b) a second container with a compositioncontained therein, wherein the composition comprises a furthertherapeutic agent. The article of manufacture in this embodimentdisclosed herein may further comprise a package insert indicating thatthe first and second compositions can be used to treat a particularcondition. Alternatively, or additionally, the article of manufacturemay further comprise a second (or third) container comprising apharmaceutically-acceptable buffer, such as bacteriostatic water forinjection (BWFI), phosphate-buffered saline, Ringer's solution anddextrose solution. It may further include other materials desirable froma commercial and user standpoint, including other buffers, diluents,filters, needles, and syringes. Preferably, the compound or compositionis packaged in a unit dosage form. The kit may further include a devicesuitable for administering the composition according to a specific routeof administration or for practicing a screening assay. Preferably, thekit contains a label that describes use of the humanized antibodycomprising an ultralong CDR3 composition.

The following are examples of the methods and compositions of thedisclosure. It is understood that various other embodiments may bepracticed, given the general description provided above.

EXAMPLES Example 1 Generation of a Humanized Antibody with an UltralongCDR3 Sequence

At least 7 antibody heavy chain variable region sequences are publiclyavailable that comprise an ultralong CDR3 of bovine origin. Thesesequences are shown in the alignment in FIG. 1. As shown in FIG. 1, theultralong CDR3s present within these variable region sequences range inlength from 56 to 61 amino acids. Strikingly, the sequence alignmentindicates that the amino acid residues positioned in the N-terminal endsof the CDR3s are particularly conserved. Following the first cysteineresidue in each of these variable region sequences, an amino acidsequence pattern of “TTVHQ” and variants thereof are found. This isunusual in that most heavy chain variable regions of most species endwith the amino acid sequence “CAK” or “CAR”. This unusual sequence motif(e.g., “TTVHQ”) may be characteristic of the structure of an ultralongCDR3.

Additionally, the Bos taurus genome was searched and an undescribedheavy chain variable region DNA sequence in the antibody locus was foundthat encodes a “CTTVHQ” motif (e.g., SEQ ID NO: 1). This variable regionsequence is designated herein as VH-UL (SEQ ID NO: 29). This sequencemotif, discovered for the first time in searching the cow genome, isimportant in antibodies that comprise an ultralong CDR3.

To produce a humanized antibody comprising an ultralong CDR3, humanvariable regions for acceptor human frameworks were identified that arehomologous to the bovine-derived VH-UL sequence (SEQ ID NO: 29). Severalmembers of the human VH4 family were identified as being homologous tothe VH-UL sequence, however none of VH4 family members contained a“CTTVHQ” motif. The sequences VH4-34*02 (SEQ ID NO: 33), VH4-39 (SEQ IDNO: 31), and VH4-59*03 (SEQ ID NO: 32) are the most homologous to theVH-UL sequence (see, e.g., FIG. 4B).

In a first exemplary method to produce a humanized antibody comprisingan ultralong CDR3, a VH4-39 human acceptor framework (SEQ ID NO: 31) isused. The nucleotides encoding the last two amino acid residues ofVH4-39 (e.g., “AR”) are removed from the VH4-39 human acceptorframework, and nucleotides encoding a “TTVHQ” motif are added to the 3′end of the DNA sequence encoding the VH4-39 human acceptor frameworkafter the nucleotides that encode the second cysteine residue of theVH4-39 human acceptor framework (e.g., after the nucleotides that codefor amino acid position 97 of SEQ ID NO: 31). Next, the DNA encoding aportion of the ultralong CDR3 from BLV1H12 (e.g., the portion of theultralong CDR3 beginning at the first glutamic acid residue (E) inBLV1H12; ETKKYQSCPDGYRERSDCSNRPACGTSDCCRVSVFGNCLTTLPVSYSYTYNYEWHVD) isfused to the 3′ end of the polynucleotide encoding the “TTVHQ” motif.Finally, DNA encoding a partial human JH4 region, beginning with theconserved tryptophan residue common to J region sequences, is added tothe 3′ end of the portion of the ultralong CDR3 sequence derived fromBLV1H12. The following antibody gene encoding a partially human antibodycomprising an ultralong CDR3 is derived:

(SEQ ID NO: 377) cagctgcagctgcaggagtcgggcccaggactggtgaagccttcggagaccctgtccctcacctgcactgtctctggtggctccatcagcagtagtagttactactggggctggatccgccagcccccagggaaggggctggagtggattgggagtatctattatagtgggagcacctactacaacccgtccctcaagagtcgagtcaccatatccgtagacacgtccaagaaccagttctccctgaagctgagctctgtgaccgccgcagacacggctgtgtattactgt act actgtgcaccagGAAACAAAAAAATACCAAAGTTGTCCTGATGGGTATAGAGAACGTTCGGATTGTAGTAACAGACCTGCTTGTGGTACTAGTGATTGTTGTCGTGTTAGTGTTTTTGGTAATTGTCTTACTACTCTTCCTGTGAGTTATAGTTATACTTACAATTACGAATGGCACGTCGATGTC TGGGGCCAGGGAACCCTGGTCACCGTCTCCTCAG Regular Font-derived from human VH4-39Underlined -derived from VH-ULBOLD BLACK-ultralong CDR3, derived from cow BLVH12ITALICS-derived from human JH4

The amino acid sequence as translated from this partially human variableregion gene is:

cagctgcagctgcaggagtcgggcccaggactggtgaagccttcggagaccctgtccctc(SEQ ID NO: 377) Q  L  Q  L  Q  E  S  G  P  G  L  V  K  P  S  E  T  L  S  L(SEQ ID NO: 378)acctgcactgtctctggtggctccatcagcagtagtagttactactggggctggatccgc T  C  T  V  S  G  G  S  I  S  S  S  S  Y  Y  W  G  W  I  Rcagcccccagggaaggggctggagtggattgggagtatctattatagtgggagcacctac Q  P  P  G  K  G  L  E  W  I  G  S  I  Y  Y  S  G  S  T  Ytacaacccgtccctcaagagtcgagtcaccatatccgtagacacgtccaagaaccagttc Y  N  P  S  L  K  S  R  V  T  I  S  V  D  T  S  K  N  Q  Ftccctgaagctgagctctgtgaccgccgcagacacggctgtgtattactgtactactgtg S  L  K  L  S  S  V  T  A  A  D  T  A  V  Y  Y  C  T  T  Vcaccaggaaacaaaaaaataccaaagttgtcctgatgggtatagagaacgttcggattgt H  Q  E  T  K  K  Y  Q  S  C  P  D  G  Y  R  E  R  S  D  Cagtaacagacctgcttgtggtactagtgattgttgtcgtgttagtgtttttggtaattgt S  N  R  P  A  C  G  T  S  D  C  C  R  V  S  V  F  G  N  Ccttactactcttcctgtgagttatagttatacttacaattacgaatggcacgtcgatgtc L  T  T  L  P  V  S  Y  S  Y  T  Y  N  Y  E  W  H  V  D  Vtggggccagggaaccctggtcaccgtctcctcag  W  G  Q  G  T  L  V  T  V  S  S

In an embodiment, this humanized VH sequence is recombinantly fusedin-frame with a human heavy chain constant region and paired with alight chain for recombinant antibody production.

In another exemplary method to produce a humanized antibody comprisingan ultralong CDR3, an ultralong CDR3 derived from BLV5B8 (SEQ ID NO: 7)is incorporated into the VH4-34 human acceptor framework (e.g., 4-34*02(SEQ ID NO: 33); or 4-34*09 (SEQ ID NO: 34), along with a portion of thehuman JH2 region to produce a humanized antibody comprising an ultralongCDR3. Next, the nucleotides encoding the last two amino acid residues ofthe VH4-34 human acceptor framework (e.g., “AR”) are removed from theVH4-34 human acceptor framework, and nucleotides encoding a “TTVHQ”motif are added to the 3′ end of the VH4-34 human acceptor frameworkafter the nucleotides that code for the second conserved cysteineresidue in the VH4-34 human acceptor framework (e.g., after thenucleotides that code for amino acid position 95 of SEQ ID NOS: 33 or34). Finally, DNA encoding a partial human JH2 region, beginning withthe conserved tryptophan residue common to J region sequences, is addedto the 3′ end of the portion of the ultralong CDR3 sequence derived fromBLV5B8. Thus, the following sequence encoding a humanized antibodyvariable region comprising an ultralong CDR3 is produced:

(SEQ ID NO: 379) caggtgcagctacaacagtggggcgcaggactgttgaagccttcggagaccctgtccctcacctgcgctgtctatggtgggtccttcagtggttactactggagctggatccgccagcccccagggaaggggctggagtggattggggaaatcaatcatagtggaagcaccaactacaacccgtccctcaagagtcgagtcaccatatcagtagacacgtccaagaaccagttctccctgaagctgagctctgtgaccgccgcggacacggctgtgtattactgt Actactgtg caccagGAAACCAGAAAAACCTGTTCTGATGGTTATATGGCTGTAGATAGTTGTGGTCGTGGTCAGAGTGATGGTTGTGTCAATGATTGCAATTGTTGTTATTATGGTTGGCGGAACTGTCGCAGGCAGCCTGCAATTCAAAGTTACGAATTTCACGTCGATGCCTGGGGCCGTGGCACCCTGGTCACTGTCTCCT CAGRegular Font-derived from human VH4-39 Underlined -derived from VH-ULBOLD BLACK-ultralong CDR3, derived from cow BLVH12ITALICS-derived from human JH2

The amino acid sequence as translated from this partially human variableregion gene is:

caggtgcagctacaacagtggggcgcaggactgttgaagccttcggagaccctgtccctc(SEQ ID NO: 379) Q  V  Q  L  Q  Q  W  G  A  G  L  L  K  P  S  E  T  L  S  L(SEQ ID NO: 380)acctgcgctgtctatggtgggtccttcagtggttactactggagctggatccgccagccc T  C  A  V  Y  G  G  S  F  S  G  Y  Y  W  S  W  I  R  Q  Pccagggaaggggctggagtggattggggaaatcaatcatagtggaagcaccaactacaac P  G  K  G  L  E  W  I  G  E  I  N  H  S  G  S  T  N  Y  Nccgtccctcaagagtcgagtcaccatatcagtagacacgtccaagaaccagttctccctg P  S  L  K  S  R  V  T  I  S  V  D  T  S  K  N  Q  F  S  Laagctgagctctgtgaccgccgcggacacggctgtgtattactgtactactgtgcaccag K  L  S  S  V  T  A  A  D  T  A  V  Y  Y  C  T  T  V  H  Qgaaaccagaaaaacctgttctgatggttatatggctgtagatagttgtggtcgtggtcag E  T  R  K  T  C  S  D  G  Y  M  A  V  D  S  C  G  R  G  Qagtgatggttgtgtcaatgattgcaattgttgttattatggttggcggaactgtcgcagg S  D  G  C  V  N  D  C  N  C  C  Y  Y  G  W  R  N  C  R  Rcagcctgcaattcaaagttacgaatttcacgtcgatgcctggggccgtggcaccctggtc Q  P  A  I  Q  S  Y  E  F  H  V  D  A  W  G  R  G  T  L  VActgtctcctcag  T  V  S  S

In an embodiment, this humanized VH sequence is then recombinantly fusedin-frame with a human heavy chain constant region and paired with alight chain for recombinant antibody production.

Thus, any heavy chain variable region can be paired with a light chainvariable region to produce a recombinant antibody. Bovine antibodiescontaining ultralong VH CDR3s typically pair with a restricted set oflambda light chains. Several human VL sequences can be used to pair withthe sequences above, including VL1-47, VL1-40, VL1-51, VL2-18, which arehomologous to the lambda region derived from Bos taurus.

Example 2 Generation of Libraries of Polynucleotides Encoding AntibodiesComprising an Ultralong CDR3

Libraries of polynucleotides encoding antibodies that comprise anultralong CDR3 may be constructed by any method known in the art. Suchpolynucleotide libraries may be present within a plurality of vectors(e.g., a library of vectors) including, for example, vectors presentwithin a plurality of host cells (e.g., a library of host cells). Thelibraries may present in any known format including, in a spatiallyaddressed format (see, e.g., WO 11/056997; and Mao et al. (2010) NatBiotech 28:1195-1202).

In an exemplary method, bovine spleen and lymph nodes were obtained fromAnimal Technologies (Tyler, Tex.), or from Texas A&M University. TotalRNA was isolated from bovine tissues from three different cows (MID1,MID10, and MID 11) using TRIzol reagent (Invitrogen, Carlsbad, Calif.,USA) followed by on column digestion of DNA using the RNeasy Mini Kit(Qiagen, Valencia, Calif., USA). Alternatively, cDNA may be obtainedfrom the lymph nodes of a bovine immunized with an antigen (e.g., BVDV).Next, RNA quantity and quality were assessed with Nanodrop (ThermalScientific), Qubit RNA and Agilent 2100 Bioanalyzer (Agilent, SantaClara, Calif., USA), following the manufacturer's protocols. Total RNAwas used as a template for cDNA synthesis catalyzed by Superscript II(Invitrogen).

The library of amplified antibody variable regions were then subjectedto deep sequencing. Briefly, bar-coded primers (Table 1) for each of thethree cows (MID1, MID10, and MID11) were used to amplify V_(H) frombovine spleen cDNA.

TABLE 1 Bar-coded primers for deep sequencing Primer # Isotype PrimersMID1 FW IgG CCTATCCCCTGTGTGCCTTGGCAGTCTCAGACGAGTGCGTTTGAGCGACAAGGCTGTAGGCTG (SEQ ID NO: 381) MID1 RV IgGCCATCTCATCCCTGCGTGTCTCCGACTCAGAC GAGTGCGTCTTTCGGGGCTGTGGTGGAGGC(SEQ ID NO: 382) MID10 FW IgM CCTATCCCCTGTGTGCCTTGGCAGTCTCAGTCTCTATGCGTTGAGCGACAAGGCTGTAGGCTG (SEQ ID NO: 383) MID10 RV IgMCCATCTCATCCCTGCGTGTCTCCGACTCAGTC TCTATGCGAGTGAAGACTCTCGGGTGTGATTC AC(SEQ ID NO: 384) MID11 FW IgM CCTATCCCCTGTGTGCCTTGGCAGTCTCAGTGATACGTCTTTGAGCGACAAGGCTGTAGGCTG (SEQ ID NO: 385) MID11 RV IgMCCATCTCATCCCTGCGTGTCTCCGACTCAGTG ATACGTCTAGTGAAGACTCTCGGGTGTGATTC AC(SEQ ID NO: 386)

Next, the amplicons of V_(H) were purified from 2% agarose gels and deepsequenced according to Roche 454 GS FLX instructions. Multiplealignments were performed with the MUSCLE algorithm (Edgar (2004)Nucleic Acids Research 32:1792-1797). MUSCLE was executed to generatemultiple long CDR H3 nucleotide alignments with relatively high gap open(−20.0) and gap extend (−10.0) penalties due to the large amount ofheterogeneity observed in the sequences. Local alignment was executedusing the Smith-Waterman algorithm with the following settings, matchscore=2.0, mismatch penalty=−1.0, gap opening penalty=−2.0, and gapextension penalty=−0.5. CDR H3s were defined by the third residuefollowing the conserved cysteine in framework 3 to the residueimmediately preceding the conserved tryptophan in framework 4. V_(H)BULwas identified by BLAST searching the bovine genome (assemblyBtau_(—)4.6.1) with multiple ultralong V_(H) sequences identified bydeep sequencing. The deep sequencing identified a total of 11,728ultralong CDR3 sequences with having a length between 44 and 69 aminoacid residues. The results of the deep sequencing are summarized inTable 2 below.

TABLE 2 Summary of deep sequencing results from bovine spleen Cow #1 Cow#1 Cow #2 Source (Bar code) (MID1) (MID10) (MID11) Ig Class IgG IgM IgMCDR H3 length range 44-66 44-68 44-69 Number of unique cysteine patterns655 449 847 Total number of unique 5633 1639 4456 long CDR H3 sequences

The results of the deep sequencing also revealed that ultralong CDR3comprise a cysteine motif (e.g., a pattern of cysteine residues) thatcomprises between 3 and 12 cysteine residues. Representative examples ofcysteine patterns are shown for the deep sequencing run for threedifferent cows (MID1, MID10, and MID11) as well as their abundance inthe run (Tables 3-5). The cysteines in the ultralong CDR3 regions aresymbolized as “C”. The amino acids between two cysteines are symbolizedas “X_(n)”. Exemplary sequences comprising cysteine motifs identifiedfrom the deep sequencing are presented in FIGS. 2A-C.

TABLE 3 Cysteine patterns identifiedin ultralong CDR3s from MID1Cysteine pattern (MID1) Abundance (%) CX₁₀ CX₅ CX₅ CXCX₇ C 10.44% CX₁₀CX₆ CX₅ CXCX₁₅ C 8.11% CX₁₁ CXCX₅ C 5.22% CX₁₁ CX₅ CX₅ CXCX₇ C 2.56%CX₁₀ CX₆ CX₅ CXCX₁₃ C 1.47% CX₁₀ CX₅ CXCX₄ CX₈ C 1.19% CX₁₀ CX₆ CX₆CXCX₇ C 1.08% CX₁₀ CX₄ CX₇ CXCX₈ C 1.05% CX₁₀ CX₄ CX₇ CXCX₇ C 0.91% CX₁₃CX₈ CX₈ C 0.91% CX₁₀ CX₆ CX₅ CXCX₇ C 0.59% CX₁₀ CX₅ CX₅ C 0.57% CX₁₀ CX₅CX₆ CXCX₇ C 0.50% CX₁₀ CX₆ CX₅ CX₇ CX₉ C 0.43% CX9CX₇ CX₅ CXCX₇ C 0.41%CX₁₀ CX₆ CX₅ CXCX₉ C 0.36% CX₁₀ CXCX₄ CX₅ CX₁₁ C 0.32% CX₇ CX₃ CX₆ CX₅CXCX₅ CX₁₀ C 0.32% CX₁₀ CXCX₄ CX₅ CXCX₂ CX₃ C 0.30% CX₁₆ CX₅ CXC 0.23%

TABLE 4 Cysteine patternsidentified in ultralong CDR3s from MID10Cysteine pattern (MID10) Abundance (%) CX₁₀ CXCX₄ CX₅ CXCX₂ CX₃ C 2.87%CX₁₀ CX₅ CX₅ C 0.73% CX₁₀ CXCX₄ CX₅ CX₁₁ C 0.67% CX₆ CX₄ CXCX₄ CX₅ C0.61% CX₁₁ CX₄ CX₅ CX₆ CX₃ C 0.55% CX₈ CX₂ CX₆ CX₅ C 0.43% CX₁₀ CX₅ CX₅CXCX₁₀ C 0.37% CX₁₀ CXCX₆ CX₄ CXC 0.31% CX₁₀ CX₅ CX₅ CXCX₂ C 0.31% CX₁₄CX₂ CX₃ CXCXC 0.31% CX₁₅ CX₅ CXC 0.31% CX₄ CX₆ CX₉ CX₂ CX₁₁ C 0.31% CX₆CX₄ CX₅ CX₅ CX₁₂ C 0.31% CX₇ CX₃ CXCXCX₄ CX₅ CX₉ C 0.31% CX₁₀ CX₆ CX₅ C0.24% CX₇ CX₃ CX₅ CX₅ CX₉ C 0.24% CX₇ CX₅ CXCX₂ C 0.24% CX₁₀ CXCX₆ C0.18% CX₁₀ CX₃ CX₃ CX₅ CX₇ CXCX₆ C 0.18% CX₁₀ CX₄ CX₅ CX₁₂ CX₂ C 0.18%

TABLE 5 Cysteine patterns identified in  ultralong CDR3s from MID11Cysteine pattern (MID11) Abundance (%) CX₁₂ CX₄ CX₅ CXCXCX₉ CX₃ C 1.19%CX₁₂ CX₄ CX₅ CX₁₂ CX₂ C 0.96% CX₁₀ CX₆ CX₅ CXCX₁₁ C 0.92% CX₁₆ CX₅CXCXCX₁₄ C 0.70% CX₁₀ CX₅ CXCX₈ CX₆ C 0.52% CX₁₂ CX₄ CX₅ CX₈ CX₂ C 0.49%CX₁₂ CX₅ CX₅ CXCX₈ C 0.47% CX₁₀ CX₆ CX₅ CXCX₄ CXCX₉ C 0.45% CX₁₁ CX₄ CX₅CX₈ CX₂ C 0.45% CX₁₀ CX₆ CX₅ CX₈ CX₂ C 0.43% CX₁₀ CX₆ CX₅ CXCX₈ C 0.36%CX₁₀ CX₆ CX₅ C 0.31% CX₁₀ CX₆ CX₅ CXCX₃ CX₈ CX₂ C 0.29% CX₁₀ CX₆ CX₅ CX₃CX₈ C 0.29% CX₁₀ CX₆ CX₅ CXCX₂ CX₆ CX₅ C 0.25% CX₇ CX₆ CX₃ CX₃ CX₉ C0.25% CX₉ CX₈ CX₅ CX₆ CX₅ C 0.22% CX₁₀ CX₂ CX₂ CX₇ CXCX₁₁ CX₅ C 0.20%CX₁₀ CX₆ CX₅ CXCX₁₃ C 0.20% CX₁₀ CX₆ CX₅ CXCX₂ CX₈ CX₄ C 0.20%

Bovine V_(H) regions were amplified from cDNA prepared in example 9using primers 5′-TTGAGCGACAAGGCTGTAGGCTG-3′ (SEQ ID NO: 387) and5′-CTTTCGGGGCTGTGGTGG-AGGC-3′ (SEQ ID NO: 388) producing a library ofantibody variable region cDNA biased for ultralong CDRs. Next, themixture of V_(H) regions was assembled by overlap PCR with bovine C_(H)1and human IgG Fc. Briefly, EcoRI and NheI sites were incorporated forligation into pFUSE expression vector, to afford a full-length heavychain library ready for expression in mammalian cells. The ligationproduct was transformed into E. coli and 500 single E. colitransformants were picked. Each transformant was then grown overnight ina separate vessel and DNA from each colony was extracted using Qiagenminprep kits (Qiagen, Inc.) and sequenced by BATJ, Inc. (San Diego,Calif.) using the oligo 5′-AGATCCAAGCTGTGACCGGC-3′ (SEQ ID NO: 389).Sequences were analyzed using VectorNTI (Invitrogen, Inc. Carlsbad,Calif.). Duplicative sequences, sequences with no insert, and sequencesencoding a CDR shorter than 35 residues were excluded. 132 clonescontaining unique long CDR heavy chain sequences were selected. Eachheavy chain in the 132 member library was then co-transfected inparallel with pFUSE expression vector encoding the invariant bovinelight chain BLV1H12 (SEQ ID NO: 412) into 293T cells, to generate asmall spatially addressed library (Mao et al. (2010) Nat Biotech28:1195-1202). 130,000 293T cells per well were plated in 24 well platesand grown overnight in 500 ul DMEM media (Invitrogen) with 10% FBS(Invitrogen), and Penicillin/streptomycin/glutamine (Invitrogen) at 37°C. and 5% CO₂. 0.5 μg of Hc-encoding pFuse vector and 0.5 μg ofLc-encoding pFuse vector were added to 25 μl of optimem (Invitrogen). 1μl of Lipofectamine 2000 or 293Fectin transfection reagent (Invitrogen)was added to 25 μl of optimem, and incubated 5 minutes. Next, theDNA-optimem mix and transfection reagent-optimem mix were combined andincubated 15 minutes, added to 293T cells, and allowed to incubate oncells 4-6 hours. Then media was aspirated from wells and replaced withfresh media, and cells were allowed to grow and secrete IgG into themedia for 4 days. Cell-culture supernatants containing IgG wereharvested in 96 well format for further testing. The chimeric antibodieswere quantified by sandwich ELISA detecting human F_(c) and screened forbinding to BVDV by ELISA.

Antibodies were then secreted into culture media and harvested in a 96well format to generate a small spatially addressed library for furthertesting including, screening for binding to BVDV by ELISA. For example,an ELISA was conducted to screen the antibody library for binding toBVDV. Briefly, killed BVDV (0.2 μg) in 100 μL DPBS was coated on 96-wellMaxiSorp ELISA plates (Nunc) for 1 hour at 37° C. Next, the plates wereblocked with 200 μL 3% BSA solution in DPBST, Dulbecco's phosphatebuffered saline, 0.25% Tween 20) for 1 hour at 37° C. Samples were thenincubated with 3% BSA in DPBST for 1 hour at 37° C. Subsequently, wellswere washed 5 times with 200 μL DPBST. Next, Goat Anti-Human IgG(Fc)-HRP conjugated antibody (KPL Inc.) was added at a 1:1,000 dilutionin blocking solution and incubated for 1 hour at 37° C. Wells were thenwashed 10 times with 200 μL DPBST. A 100 μL working solution ofQuantaBlu (Pierce) was added to each well and incubated for 5 minutes atroom temperature before plates were read in a SpectraMax M5 plate readerat ex325/em420 nm. Several candidate binders were identified. Clone H12has a 63-residue CDR3 with 6 cysteine residues and was able to stronglybind BVDV in a dose dependent fashion.

Additionally, binding of the chimeric recombinant antibodies to BVDVantigens was evaluated by immunocytometric analysis of transfected humanembryonic kidney (HEK) 293A cells (Invitrogen), as previously described(see, e.g., Njongmeta et al. (2012) Vaccine 30:1624-1635). Briefly, HEK293A monolayers grown in 6-well tissue culture plates were transfectedwith 2 μg/well of plasmid (pCDNA3.3, Invitrogen) encoding BVDV antigens(N^(pro), E2, or non-structural proteins NS2-3) using Lipofectamine 2000reagent (Invitrogen), and incubated for 48 hr at 37° C. with 5% CO₂. Themonolayers were fixed with ice-cold 100% methanol for 10 minutes, rinsedwith PBS, and after blocking for 1 hour with PBS containing 5% fetalbovine serum (blocking buffer), the monolayers were incubated at roomtemperature for 1 hr with 10 μg/ml of a mouse anti-FLAG M2-alkalinephosphatase (AP)-conjugate (Sigma) in blocking buffer or 10 μg/ml of thechimeric recombinant antibodies (H12 or B8). Monolayers transfected withempty vector were similarly reacted to serve as negative controls and,following washes in blocking buffer, the monolayers probed with thechimeric recombinant antibodies were incubated with a 1/200 dilution ofAP-conjugated goat anti-Human IgG (Fc specific) mAb (Sigma) in blockingbuffer for 1 hr. Following washes in blocking buffer, the AP activity inall the wells was detected using Fast Red AS-MX substrate (Sigma).Stained cells were visualized and photographed using an IS70 invertedoptical microscope (Olympus, Japan) equipped with a camera. H12 stronglybinds HEK293A cells transfected with the NS2-3 non-structural proteinsof BVDV but weakly bound to untransfected cells while B8 had weakbinding to both HEK293A cells transfected with the NS2-3 non-structuralproteins of BVDV and untransfected cells.

Example 3 Construction of Vector Comprising an Antibody with anUltralong CDR3

Any vector known in the art may be used, or may be modified to be used,for cloning and/or expression of a nucleotide sequence encoding a heavychain variable region that comprises an ultralong CDR3. Such vectors mayoptionally comprise, or be modified to comprise, a nucleotide sequenceencoding the Fc portion of a human immunoglobulin (e.g., IgG) linked tothe nucleotide sequence encoding the heavy chain variable regioncomprising an ultralong CDR3. Additionally, the nucleotide sequenceencoding the heavy chain variable region comprising the ultralong CDR3may be modified according to known methods such that the ultralong CDR3can accept a nucleotide sequence encoding a non-bovine (e.g.,non-antibody or human) sequence including, for example, byunidirectional cloning with restriction enzymes. Any vector known in theart may also be used, or may be modified to be used, for cloning and/orexpression of a nucleotide sequence encoding a light chain variableregion.

In an exemplary method, a vector may be modified by recombinanttechniques to comprise a nucleotide sequence encoding a heavy chainvariable region having an ultralong CDR3 linked to a nucleotide sequenceencoding an IgG Fc. Briefly, a nucleotide sequence encoding CH1-CH2-CH3of human IgG1 (SEQ ID NO: 390) was amplified by PCR and assembled viastrand overlap elongation. Next, a compatible cohesive-end strategy wasemployed to replace the human Fc sequence encoded in vectorpFUSE-hIgG2-Fc2 (SEQ ID NO: 457, InVivogen, San Diego Calif.) withCH1-CH2-CH3 of human IgG1, which destroyed the existing 3′ NheI site inthe pFUSE-hIgG2-Fc2 vector and generated an NheI site at the 5′ end ofSEQ ID NO: 390. The modified pFUSE-hIgG2-Fc2 vector (“HC pFuse”, SEQ IDNO: 458) allows insertion of VH fragments between the signal sequenceand the nucleotide sequence encoding CH1-CH2-CH3 of human IgG1 using theexisting EcoRI site and the newly introduced NheI site. For example, theVH region from bovine antibody BLV1H12 (SEQ ID NO: 392) was amplified byPCR and subcloned in-frame between the signal sequence and nucleotidesequence encoding CH1-CH2-CH3 of human IgG1 in the HC pFuse vector usingEcoRI and NheI restriction enzymes generating SEQ ID NO: 393.

Alternatively, nucleotide sequences encoding non-bovine sequences wereinserted into the nucleotide sequence encoding the CDR3 of BLV1H12 heavychain. Briefly, a pair of BsaI sites were introduced by PCR strandoverlap extension into the nucleotide sequence encoding the CDR3 ofBLV1H12 (SEQ ID NO: 395). The modified nucleotide sequence incorporatingthe BsaI sites within the CDR3 encoding sequence of BLV1H12 was thensubcloned in-frame between the signal sequence and the nucleotidesequence encoding CH1-CH2-CH3 of human IgG1 in the HC pFuse vectordescribed above using EcoRI and NheI restriction enzymes. Next,non-antibody sequences including cDNA encoding for interleukin 8 (IL-8,SEQ ID NO: 475), interleukin 21 (IL-21, SEQ ID NO: 480) andCXCL12/SDF-1alpha (SEQ ID NO: 479) (Origene) and oligoprimers encodingthe peptide hormone somatostain (SEQ ID NO: 477), the venom peptidesProTx-II (SEQ ID NO: 481) and chlorotoxin (SEQ ID NO: 478), and thesynthetic conotoxin peptide ziconotide (SEQ ID NO: 476) (IDTDNA) weremodified by PCR amplification using oligoprimers with BsaI flanks tocomprise BsaI flanks to produce non-bovine sequences with BsaI flanksfor insertion into the CDR3 of BLV1H12. Next, the BsaI flanks in themodified non-antibody sequences were cut with BsaI and ligated, inframe, with the BLV1H12 BsaI digested vector, thereby inserting thenucleotide sequence encoding the non-antibody sequence into the BLV1H12heavy chain variable region and replacing a portion (e.g., cysteine-richportion) of the ultralong CDR3, and in-frame with the sequence encodingBVL1H12 variable region and CH1-CH2-CH3.

Similarly, a vector was modified by recombinant techniques to comprise anucleotide sequence encoding a light chain. Briefly, the BLV1H12 lightchain sequence (SEQ ID NO: 412) was amplified by PCR to introduce EcoRIand NheI ends. The BLV1H12 light chain variable region sequence was thendigested with EcoRI and NheI and subcloned into pFUSE-hIgG2-Fc2,deleting the portion of pFUSE-hIgG2-Fc2 encoding Fc, and replacing itwith only light chain sequence (SEQ ID NO: 459).

In addition, overlap PCR was used to amplify and join sequence fromBLV1H12 light chain variable region and human lambda light chainconstant region (SEQ ID NO: 474). This was amplified by PCR to introduceEcoRI and NheI ends. The hybrid BLV1H12 with human lambda sequence wasthen digested with EcoRI and NheI and subcloned into pFUSE-hIgG2-Fc2,deleting the portion of pFUSE-hIgG2-Fc2 encoding Fc, and replacing itwith only light chain sequence.

Example 4 Expression of Polynucleotides Coding for Antibodies thatComprise an Ultralong CDR3

Polynucleotides coding for antibodies comprising an ultralong CDR3 maybe expressed including, transiently expressed, in a host cell by anymethod known in the art.

In an exemplary method, the vectors comprising the heavy and lightchains generated in Example 2 may be transfected into either 293T cellsor Freestyle™ 293-F cells.

For example, 130,000 293T cells per well were plated in 24 well platesand grown overnight in 500 μl DMEM media (Invitrogen) with 10% FBS(Invitrogen), and penicillin/streptomycin/glutamine (Invitrogen) at 37°C. and 5% CO₂. Next, 0.5 μg of Heavy chain-encoding pFuse vector (e.g.,generated in Example 2) and 0.5 μg of Light chain-encoding pFuse vector(e.g., generated in Example 2) were added to 25 μl of Opti-MEM(Invitrogen). Subsequently, 1 μl of Lipofectamine 2000 or 293Fectintransfection reagent (Invitrogen) was added to 25 μl of Opti-MEM, andincubated 5 minutes. Then the dna-Opti-MEM solution and transfectionreagent-Opti-MEM solution were combined and incubated for 15 minutes,added to 293T cells, and allowed to incubate on cells for 4-6 hours.Then media was aspirated from wells and replaced with fresh media, andthe cells were allowed to grow and secrete IgG into the media for 2-6days.

Additionally, for example, 1×10⁶ 293 Freestyle suspension cells/ml weregrown overnight in Freestyle™ 293 Expression Medium (Invitrogen), andpenicillin/streptomycin/glutamine (Invitrogen) at 37° C. and 5% CO₂.Next, for each milliliter of cells, a 30 μl solution was made in bufferPBS comprising 0.5 μg Heavy chain-encoding pFuse DNA and 0.5 μg ofLc-encoding pFuse. Additionally, for each milliliter of cells, asolution comprising 1 μl of 293Fectin transfection reagent was added to30 μl PBS and incubated 5 minutes. Subsequently, the DNA andlipofectamine solutions were combined and incubated 15 minutes beforeadding the mixture to the cells. The cells were then allowed to grow andsecrete IgG into media for 2-6 days.

After the growth period for the 293T cells or Freestyle™ 293-Fsuspension cells, media was harvested, and IgG secreted into thesupernatant was evaluated by sandwich ELISA. Briefly, Fc-specific antiHuman IgG (Cat I2136, Sigma-Aldrich) was diluted 1:1000 in PBS andcoated onto maxisorp plates (Nunc). Next, plates were blocked with 2%BSA in TBST, washed, and IgG secreted supernatants were incubated for 1hour. After washing with TBST, the appropriate HRP conjugated anti-Lightchain antibody is diluted 1:1000 in TBST and incubated 1 hour (antikappa-HRP, Cat#A-7164, Sigma-Aldrich; anti-lambda-HRP, Cat#2070-05,Southern Biotech). After washing with TBST, HRP was detected with TMB(Cat#TMBS-1000-01, BioFX), and neutralized with 0.6M H₂SO₄.Subsequently, absorbance (A450) was measured, and compared to a standardcurve of known IgG concentration to determine the concentration of humanantibody in cell culture supernatant.

The yield of antibody from supernatants from cells transfected withheavy chain constructs encoding BLV1H12 with human CH1-CH2-CH3 and areplacement of at least a portion of CDR3 (generated in Example 3) and alight chain construct encoding BLV1H12 LV-human lambda LC was determinedby ELISA, and normalized to the yield of BLV1H12-IL8 (Table 6). TheELISA indicated that some sequences (e.g., zinconotide) that were usedto replace a portion of CDR3 have a minor impact on expression of theantibody, while some sequences (e.g., somatostatin, chlorotoxin,SDF1(alpha), IL21) that were used to replace a portion of CDR3 had amodest impact on expression of the antibody, and other sequences(ProTxII) had an even greater impact on expression of the antibody, ascompared to BLV1H12-IL8 (the highest expressor) (Table 6).

TABLE 6 Expression yield of BLV1H12 with replacements to Long CDR3Normalized Yield (% Heavy Chain V region Light Chain of highestexpressor) BLV1H12-IL8 BLV1H12-HuLambdaC 100 BLV1H12-ZiconotideBLV1H12-HuLambdaC 94.7 BLV1H12-Somatostatin BLV1H12-HuLambdaC 46.5BLV1H12-Chlorotoxin BLV1H12-HuLambdaC 39.7 BLV1H12-SDF1(alpha)BLV1H12-HuLambdaC 38.9 BLV1H12-IL21 BLV1H12-HuLambdaC 32.3BLV1H12-ProTxll BLV1H12-HuLambdaC 2.1

Example 5 Evaluation of Human Germline Sequences Comprising an UltralongCDR3 with a Non-Bovine Sequence

Human germline sequences that comprise an ultralong CDR3 may beevaluated by any method known in the art to identify those humangermline sequences that permit expression of an ultralong CDR3 thatcomprises a non-bovine sequence.

In an exemplary method, overlap PCR was used to insert BsaI sites intohuman germline variable regions VH1-24, VH1-46, VH1-69, VH3-23, VH4-4,and VH4-34. Next, PCR was used to introduce EcoRI and NheI sites forsub-cloning in between the signal sequence and CH1-CH2-CH3 region of theHC pFuse vector comprising BLV1H12 generated in Example 2. Subsequently,the IL-8-GSG cassette (SEQ ID NO: 399) was introduced into the BsaIsites of each human germline construct, giving VH1-24+CDR3-IL8 (SEQ IDNO: 425), VH1-46+CDR3-IL8 (SEQ ID NO: 426), VH1-69+CDR3-IL8 (SEQ ID NO:427), VH3-23+CDR3-IL8 (SEQ ID NO: 428), VH4-4+CDR3-IL8 (SEQ ID NO: 429),and VH4-34+CDR3-IL8 (SEQ ID NO: 430). Next, each pFuse vector encoding ahuman germline heavy chain and CDR3-IL8 construct was co-transfectedwith pFuse vector encoding BLV1H12 LV (SEQ ID NO: 474), and allowed toexpress and secrete these IgGs into the media as described in Example 4.ELISA was then used to determine IgG yield as described in Example 4.Yields of the constructs were determined, and normalized to the highestexpressing construct. Surprisingly, the CDR3 from cow is not readilytransposable to any human heavy chain variable region. VH4-4 had thehighest yield, despite VH4-34 having the closest sequence homology tothe BLV1H12 sequence (Table 7).

TABLE 7 Expression Yield of Humanized Heavy Chains with Ultralong CDR3s(removed last column of values, with IgG nM, only showing normalizedvalues. Heavy Chain Normalized Yield (% of Variable Region: highestexpressor) BLV1H12 + CDR3IL8 100 BLV1H12 58.4 VH1-24 BLVCDR3IL8 4.4VH1-46 BLVCDR3IL8 2.4 VH1-69 BLVCDR3IL8 1.4 VH3-23 BLVCDR3IL8 14.7 VH4-4BLVCDR3IL8 22.5 VH4-34 BLVCDR3IL8 5.4

Example 6 Evaluation of Antibodies that Comprise an Ultralong CDR3 witha Non-Bovine Sequence

Antibodies comprising an ultralong CDR3 with a non-bovine sequence(e.g., a replacement of at least a portion of the CDR3 with a non-bovinesequence) including, humanized antibodies, may be evaluated by anymethod known in the art for binding of the non-bovine sequence to itsbinding partner including, for example, flow cytometry.

In an exemplary method, BLV1H12 IgG comprising a CDR3 with an IL-8insert (e.g., the IL-8 sequence replaced a portion of the CDR3) wasevaluated for binding to CXCR1 expressing cells by flow cytometry.Briefly, a cell line expressing functionally validated CXCR1 derivedfrom U2OS cells was obtained from DiscoveRx and cultured permanufacturer's instructions (Cat#93-0226C3, DiscoveRx Corporation,Freemont, Calif.). The parental cell line U2OS was obtained from ATCCand cultured under the same conditions as the CXCR1 cells. Cell culturesupernatants were then tested for binding to cells by flow cytometry.The adherent U2OS or CXCR1-U2OS cells were dissociated with Accutase(Innovative Cell Technologies, Inc., San Diego, Calif.), neutralizedwith an equal volume of media containing 10% serum, centrifuged at 1000g, and resuspended in PBS with 2% BSA. Next, cells were dispensed intomicrotiter plates to achieve between 30,000 to 300,000 cells per well,centrifuged again, and resuspended in cell culture supernatantcontaining expressed IgG, or a dilution of IgG-containing cell culturesupernatant. A fluorescent-conjugated anti-Human Fc antibody was used todetect binding of the expressed antibody to cells. Subsequently, cellfluorescence was measured by flow cytometry (e.g., FACS), and medianArbitrary Fluorescence Units (AFU) were calculated for each combinationof antibody and cell type tested, revealing the extent of IgG binding tothose cells. The ratio of median fluorescence (IgG binding) ofCXCR1-U2OS cells versus U2OS parental cells shows that the BLV1H12 IgGcomprising a CDR3 with an IL-8 insert has specificity for CXCR1 (Table8).

TABLE 8 Binding of BLV1H12 frameworks to CXCR1 U2OS cells ULcowV (MedianULcowV + IL8 (Median Arbitrary Fluorescence Arbitrary Fluorescence Units(AFU)) Units (AFU)) Parental U2OS 4 76 CXCR1-U2OS 4 707

Additionally, the human germline CDR3-IL8 IgGs described in Example 5were evaluated for binding to CXCR1 expressing cells by flow cytometryas described above. IgG binding to CXCR1-U2OS cells is indicated byhigher fluorescence values, but non-specific binding to U2OS parentalcells is also detectable. For a given IgG with CDR3-IL-8, specificbinding to CXCR1 is revealed by the ratio of fluorescence on CXCR1-U2OScells to the fluorescence on parental U2OS cells (Table 9). While theBLV1H12 supported strong and specific binding to CXCR1 (Table 8), theIL-8 in human germline IgGs showed either weaker binding to CXCR1, ornon-specific interaction as seen in strong binding to both CXCR1-U2OScells as well as the parental control cells. The most specificinteraction to CXCR1 of IL-8 within a human germline IgG was seen withVH4-34.

TABLE 9 Binding of IgGs with CDR3-IL8 to CXCR1 U2OS cells Ratio ofCXCR1/ IgG with HC V region: Parental U2OS CXCR1-U2OS Parental BLV1H12 59 1.9 VH1-24 + CDR3-IL8 5 23 4.3 VH1-46 + CDR3-IL8 5 6 1.1 VH1-69 +CDR3-IL8 20 78 4.0 VH3-23 + CDR3-IL8 534 1443 2.7 VH4-4 + CDR3-IL8 10073079 3.1 VH4-34 + CDR3-IL8 70 648 9.3

In another exemplary method, IL-8 activation of the CXCR1 receptor wastested using the CXCR1-U2OS DiscoveRx cells described above(Cat#93-0226C3, DiscoveRx). The DiscoveRx cells are engineered such thatupon activation by ligand, the resultant beta-arrestin recruitment tothe GPCR also causes activation of a luminescent reporter enzyme presentcell line. Lysis reagents and luminescence substrate are included in thePathHunter Detection Kit (Cat#93-001, DiscoveRx) which was usedfollowing manufacturer's instructions. U2OS-CXCR1 cells were plated at15,000 cells per well and serum starved overnight in EMEM media withoutserum. Next, media was removed and cells were incubated 1 hour at 37° C.with 80 μl of 1:1 EMEM and PBS, containing dilutions of either IL-8 orIgG with IL-8 insertion in CDR3, or control antibody. After 1 hour, 40μl of PathHunter Detection reagent mix was added. Subsequently, after anhour at room temperature the luminescence in each well was measuredusing a luminescence plate reader. Higher luminescence signal revealsmore activation of the CXCR1 receptor at the tested concentrations ofIL-8 or IgG. IgGs were purified by scaling up the transfection method ofExample 4, and purification of the IgG from media using protein Asepharose following manufacturer's instructions (Cat#17-1279-03 GEHealthcare) and dialysis post-elution into PBS. Protein yield wasdetermined by A280 and calculated molar extinction coefficient.Increasing concentrations of BLV1H12-IL8 IgG activated CXCR1 somewhatsimilarly to the activation observed with IL-8, whereas increasingconcentration of BLV1H12 IgG had no effect on CXCR1 activation (Table10).

TABLE 10 Activation of CXCR1 by IL-8 as soluble cytokine or as CDR3replacement IL-8 (average BLV1H12-IL8 IgG IgG_BVL1H12 IgG nM RLU)(average RLU) (average RLU) 500.00 5720 6641 484 166.67 6770 6207 52555.56 7365 5509 511 18.52 7295 5071 529 6.17 5869 4428 517 2.06 41103645 495 0.69 1939 2651 516 0.23 940 1515 455 0.08 504 822 461 0.01 440435 460

Additionally, antibodies in which IL-8 was grafted into the VH4-4 humangermline variable region were tested for activation of CXCR1. IgG withVH4-4+CDR3-IL8 (SEQ ID NO: 429) was compared to BLV1H12+CDR3-IL8, andIgGVH4-4 CDR3 BsaI (lacking the IL-8 insert) (SEQ ID NO: 431). A singleconcentration of soluble IL-8 was tested as a positive control for assayfunction at 31.5 nM and gave activation of 55525 average RLU. (Table11). Although the IgG with insertion of IL-8 into the human VH4-4variable region did activate CXCR1, it was not as potent in equal doseto the IgG with BLV1H12 sequence.

TABLE 11 Activation of CXCR1 by IgGs with CDR3 IL-8 VH4-4 + BLV1H12 +CDR3-IL8 VH4-4 + CDR3-IL8 (average CDR3-Bsal IgG (nM) (average RLU) RLU)(average RLU) 261.500 56349 36481 7545 87.167 52128 29623 7139 29.05647621 24889 7104 9.685 39280 15545 7174 3.228 34544 10233 7034 1.07623700 8012 7184 0.359 13278 7338 6687 0.120 8867 7513 7331 0.040 77367323 6973 0.013 7329 6956 7048 0.004 7240 7067 7387 0.001 7437 7142 7500

Example 7 Modification of Humanized Antibodies Comprising an UltralongCDR3

Humanized antibodies generated in Example 5 may be modified to compriseone or more amino acid substitutions in heavy chain CDR1 and/or CDR2.Such amino acid substitutions may be introduced into a human germlineCDR1 and CDR2 at positions that are hypothesized to interact with CDR3.

In an exemplary method, certain residues in VH4-34 CDR1 and/or CDR2 weresubstituted with corresponding CDR1 and/or CDR2 residues from BLV1H12.Briefly, the pFuse vector encoding heavy chain VH4-34 CDR3-IL8 wasmodified by overlap PCR to replace all of CDR1 with sequence fromBLV1H12 (VH4-34+CDR3-IL8_CDR1 Cow, SEQ ID NO: 432) or all of CDR2 withsequence from BLV1 H12 (VH4-34+CDR3-IL8_CDR2 Cow, SEQ ID NO: 433).Additionally, overlap PCR was used to introduce point mutants G31D andY32K into CDR1 (VH4-34+CDR3-IL8_CDR1 G31D, Y32K, SEQ ID NO: 434) orpoint mutant E50S into CDR2 (VH4-34+CDR3-IL8_CDR2 E50S, SEQ ID NO: 435).These heavy chain constructs were paired with BLV1H12 light chain andwere expressed as described in Example 4. Yield and CXCR1 binding weredetermined as described in Example 6 (Table 12).

TABLE 12 CDR1 and 2 modification of VH4-34 CDR3-IL8 IgG IgG Yield FACSCXCR1/ Heavy chain normalized Parental Ratio BLV1H12 100 1.9 VH4-34 +CDR3-IL8 20 9.3 VH4-34 + CDR3-IL8 + Cow CDR1 29 2.1 VH4-34 + CDR3-IL8 +Cow CDR2 9 8.0 VH4-34 + CDR3-IL8 + E31D, Y32K 19 8.1 VH4-34 + CDR3-IL8 +E50S 27 4.0

Example 8 Pairing of Heavy Chain Comprising an Ultralong CDR3 with aHuman Light Chain

Antibodies that comprise an ultralong CDR3 including, antibodies thatcomprise an ultralong CDR3 where at least a portion of the CDR3 has beenreplaced by a non-bovine sequence, may be paired with a human lightchain.

In an exemplary method, BLV1H12+CDR3-IL8 flexibility to pairproductively with human germline light chains was explored byco-transfecting pFuse vector encoding heavy chain BLV1H12+CDR3-IL8 withpFuse vectors encoding each of several human germline light chains(e.g., SEQ ID NOs: 445-456), or BLV1H12 light chain (SEQ ID NO: 412).These human germline light chain sequences were synthesized (Genscript,Inc) and amplified by PCR as in Example 3 for subcloning via EcoRI andNheI into the pFUSE LC vector. BLV1H12+CDR3-IL8 encoding pFUSE vectorwas cotransfected with pFUSE vectors encoding light chains as in Example3. Secreted IgGs were then tested by FACS as in Example 5 for specificbinding to CXCR1 cells (Table 13). Human germ line light chains did notreadily support the function of IL-8 when expressed as BLV1H12+CDR3.

TABLE 13 Evaluation of BLV1H12 + CDR3-IL8 when paired with germlinehuman light chains Light chain FACS CXCR1/Parental Ratio A20J1 0.8 A27J30.9 L6J1 0.8 L25J1 1.3 V1-2J7 0.8 V1-7J1 0.6 V1-11J2 0.8 V1-13J5 2.9V1-16J6 0.6 V2-13J2 0.9 V2-14J4 1.0 V2-15J7 1.1 V2-17J2 2.0 V3-4J1 1.2V5-4J2 0.8 BLV1H12 5.0

Alternatively, using the BLV1H12 light chain variable region as a guide,the human germline sequences identified with closest homology were V1-47and V1-51. These light chain sequences were synthesized (SEQ ID NO: 455,456) (IDTDNA, Inc.) with the desired EcoRI and NheI restriction sitesfor subcloning into the pFuse vector. Subsequently, pFuse vectorencoding V1-47 or V1-51 were paired with pFuse vectors encodingVH4-34+CDR3-IL8, the VH4-34+CDR3-IL8 with the CDR1 or CDR2 modificationsdescribed in Example 6 (SEQ ID NOs: 432-435), as well as vectorsencoding the combinations of both CDR1 and CDR2 modifications (e.g.,VH4-34+CDR3-IL8_CDR1 Cow_CDR2 Cow, SEQ ID NO: 436; VH4-34+CDR3-IL8_CDR1Cow_CDR2 E50S, SEQ ID NO: 437; VH4-34+CDR3-IL8_CDR1 G31D, Y32K_CDR2 Cow,SEQ ID NO: 438; VH4-34+CDR3-IL8_CDR1 G31D, Y32K_CDR2 E50S, SEQ ID NO:439). These IgGs were expressed, yield was determined by ELISA, andCXCR1 binding specificity was measured by flow cytometry as describedabove (Table 14).

TABLE 14 Expression yield and CXCR1 specificity for VH4-34 CDR3-IL8 IgGshaving CDR1 and CDR2 modifications and paired with Lc V1-47 or V1-51CXCR1/Parental HC VH4-34 CDR3-IL8+ nM IgG Ratio Hc-CDR1 Hc-CDR2 V1-47V1-51 V1-47 V1-51 G31D Y32K VH4-34 1 2.5 3.6 3 Cow VH4-34 3 8.5 5.1 2.4VH4-34 VH4-34 1.5 −0.4 2.6 2.9 G31D Y32K E50S 2 4.6 1.4 3 Cow E50S —22.8 2.6 3.1 VH4-34 E50S 3.3 3.3 3.3 1.8 G31D Y32K Cow −0.1 2.3 2 2.6Cow Cow 0.7 4.9 4.6 3.1 VH4-34 Cow 0.6 0.6 2.5 3.9

Example 9 Modification of Human Light Chain and Pairing with Heavy ChainComprising an Ultralong CDR3

Human germline light chains including, light chains that may be pairedwith a heavy chain comprising an ultralong CDR3, may be modified by anymethod known in the art. Such modifications may include the substitutionof certain amino acid residues in the human light chain to thoseresidues at corresponding positions in a bovine light chain sequence.The modified light chains may improve the yield of the antibodycomprising the ultralong CDR3 and/or increase its binding specificity.

In an exemplary method, variants of V1-51 were made by overlap PCR andsubcloned into pFuse vector for expression as described in Example 4.The engineered variants of V1-51 had: i) substitutions 129V and N32Gintroduced in CDR1 (SEQ ID NO: 440), ii) residues DNN (amino acids51-53) in CDR2 changed to GDT (SEQ ID NO: 441), iii) residues DNNKRP(SEQ ID NO: 471) in and near CDR2 changed to GDTSRA (SEQ ID NO: 472), oriv) the 14 residues at the N-terminus were made identical to the first14 resides of BLV1H12 light chain with point mutations S2A, T5N, P8S,A12G, A13S, and P14L (SEQ ID NO: 443) or v) combining the changes setforth in ii) and iv) (SEQ ID NO: 444). These V1-51 variants were pairedwith heavy chains encoding VH4-34+CDR3-IL8 (SEQ ID NO: 430),VH4-34+CDR3-IL8_CDR1 Cow (SEQ ID NO: 432), VH4-34+CDR3-IL8_CDR2 Cow (SEQID NO: 433), or VH4-34+CDR3-IL8_CDR1 Cow CDR2 Cow, (SEQ ID NO: 436).Transfections and ELISA were carried out as described above, and flowcytometry was used to evaluate CXCR1 binding specificity as previouslydescribed, with the modification that cells were resuspended in 2% BSAin PBS plus 2 ug/ml Heparin sulfate, and IgGs were normalized to 10 nMduring incubation on cells. Only certain combinations of heavy and lightchains supported detectable expression (Table 15). Those combinationsthat expressed heavy and light chains were tested for CXCR1 bindingspecificity (Table 16).

TABLE 15 Expression yield (nM IgG) for VH4-34 + CDR3-IL8 variants andV1-51 variants VH4-34 VH4-34 CDR3- CDR3-IL8 VH4-34 IL8 CDR1-Cow VH4-34CDR3-IL8 CDR2- &CDR2- CDR3-IL8 CDR1-Cow Cow Cow Hc CDR1: Human Cow HumanCow CDR2: Human Human Cow Cow V1-51 1 5 0 13 V1-51 CDR1 I29V, N32G −1 50 3 V1-51 CDR2 DNN to GDT −1 23 −1 5 V1-51 CDR2 DNNKRP (SEQ ID NO: −1 41 23 471) to GDTSRA (SEQ ID NO: 472) V1-51 0 38 −1 22 S2A, T5N, P8S,A12G, A13S, P14L V1-51 0 37 0 1 S2A, T5N, P8S, A12G, A13S, P14L & DNN toGDT

TABLE 16 CXCR1 specificity for VH4-34 + CDR3-IL8 variants and V1-51variants VH4-34 CDR3-IL8 VH4-34 CDR1- VH4-34 CDR3-IL8 Cow & VH4-34CDR3-IL8 CDR2- CDR2- CDR3-IL8 CDR1-Cow Cow Cow Hc CDR1: Human Cow HumanCow CDR2: Human Human Cow Cow V1-51 nt 7.2 nt 11.1 V1-51 CDR1 I29V, N32Gnt 8.9 nt 11.8 V1-51 CDR2 DNN to GDT nt 5.6 nt 16.7 V1-51 CDR2 DNNKRP(SEQ ID NO: nt 8.0 nt 6.9 471) to GDTSRA (SEQ ID NO: 472) V1-51 nt 4.7nt 12.2 S2A, T5N, P8S, A12G, A13S, P14L V1-51 nt 6.8 nt S2A, T5N, P8S,A12G, A13S, P14L & DNN to GDT

Example 10 Preparation of Antibody Libraries with Ultralong CDR3Sequences

Libraries may be generated that comprise an ultralong CDR3 including,for example libraries that comprise at least a portion of an ultralongCDR3, within an antibody framework (e.g., a heavy chain framework). Suchlibraries may comprise a diversity of ultralong CDR3 sequences, adiversity of one or more residues that are positioned between one ormore cysteine residues in the cysteine domain of the ultralong CDR3, ora diversity of non-bovine peptides that may be inserted (e.g., replace aportion of) in the ultralong CDR3. The antibody framework may be derivedfrom a bovine sequence such as VH-UL, a human germline sequence, or amodified human germline sequence such as described in Example 7. Heavychains with diverse ultralong CDR3 may be paired with light chains ofbovine, human, or modified composition (see, e.g., Example 9) forexpression of a library of antibody or antibody fragments comprising adiverse ultralong CDR3.

In an exemplary method, a library is generated in which the librarycomprises a diversity of ultralong CDR3 sequences (e.g., the diversityin the library resides in that the library contains a plurality ofdiverse ultralong CDR3 sequences). For example, a plurality of diverseultralong CDR3 sequences is obtained from cDNA extracted from the spleenand/or lymph nodes from either immunized or non-immunized cows.Alternatively, a plurality of diverse ultralong CDR3 sequences iscaptured as information from cDNA by sequencing technology, such asdescribed in Example 2. cDNA-derived cow sequences are then amplifiedfrom the isolated cDNA or synthesized from sequencing of cDNA, anddiverse CDR3 sequences are inserted into an antibody framework forexpression of IgGs with ultralong CDR3 sequences, producing a library ofIgGs with CDR3s derived from cows. The IgG library can exist in anyformat, including as a spatially addressed array see, e.g., WO11/056997; and Mao et al. (2010) Nat Biotech 28:1195-1202).

In another exemplary method, a library is generated in which members ofthe library comprise an ultralong CDR3 with a certain cysteine domain,or multiple cysteine domains, wherein the members are diverse in one ormore residues that are positioned between one or more cysteine residuesin the cysteine domain. For example, in the sequence CX₁₀CX₅CX₅CXCX₇C(SEQ ID NO: 41), a library is generated whereby any X residue ischanged, or combination of X residues are changed, to produce diversitywithin CDR3. Such diversity is introduced by degenerate nucleotidesynthesis, error prone PCR, gene synthesis, or any other method known inthe art to make changes in nucleotide sequences. These ultralong CDR3loops are then integrated with sequence encoding the antibody framework.Heavy chain sequences are then paired with human or modified human lightchain sequences for co-transfection and expression to comprise anantibody library engineered from bovine CDR3s.

In another exemplary method, a library is generated in which members ofthe library comprise an ultralong CDR3 with diversity in a non-bovinesequence inserted into (e.g., replace a portion of) the ultralong CDR3.Ultralong CDR3s tolerate large non-bovine sequence insertions (e.g.,cytokines, peptide hormones, signaling domains, and constituent proteinsof arthropod toxins or reptile venoms) including, for example, cysteinerich insertions, within an antibody framework, and support theindependent function of the peptide encoded by the non-bovine sequence,as demonstrated in Example 4 and Example 6. Sequences encodingnon-bovine sequences are amplified by PCR from cDNA or synthesized, andincorporated with or without linker sequences, into an antibody sequencesuch that they are expressed within, in place of, or replace at least aportion of, an ultralong CDR3. Exemplary methods to insert a non-bovinesequence into a vector for expression are set forth in Example 3 above.Heavy chain sequences are then paired with human or modified human lightchain for co-transfection and expression. For example, a non-bovinesequence is inserted into HC pFUSE, encoding VH4-34*02 with CDR1 andCDR3 modifications from BLV1 H12. Briefly, the portion of the HC pFusevector comprising a BsaI cassette (see, Example 3; bolded in thesequence below) which is flanked on both sides by a portion of anultralong CDR3 (underlined sequence below) is replaced by a non-bovinesequence.

(SEQ ID NO: 472) caggtgcagctacagcagtggggcgcaggactgttgaagccttcggagacgctgtccctcacctgcacagcaagcgggttttcactgagcgacaaggcagtgggatggattcgccagcccccagggaaggggctggagtggattggggaaatcaatcatagtggaagcaccaactacaacccgtccctcaagagtcgagtcaccatatcagtagacacgtccaagaaccagttctccctgaagctgagctctgtgaccgccgcggacacggctgtgtattactgtacctctgtgcaccaggaaactaagaaataccagagcgagacctactatggt tcgggtctctcttatacctacaattatgaatggcatgtggatgtctggggacagggcctgctggtgacagtctctagtgctagc

After replacement of the BsaI cassette with the non-bovine sequence thenon-bovine sequence (referred to as insert in bold text in the sequencebelow) is positioned such that it is flanked on both sides by a portionof the ultralong CDR3.

(SEQ ID NO: 473) qvqlqqwgagllkpsetlsltctasgfslsdkavgwirqppgkglewigeinhsgstnynpslksrvtisvdtsknqfslklssvtaadtavyyctsvhgetkkyqs- insert -sytynyewhvdvwgqgllvtvssas

Heavy chain sequences are then paired with human or modified human lightchain for co-transfection and expression.

Embodiments of the present subject matter described above, some of whichare set forth below, may be beneficial alone or in combination, with oneor more other embodiments. Such embodiments include:

Embodiment 1. A humanized antibody or binding fragment thereofcomprising an ultralong CDR3. In some embodiments, the humanizedantibody or binding fragment thereof comprises one or more humanvariable region framework sequences.

Embodiment 2. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the ultralong CDR3 is 35 amino acids in length orlonger, 40 amino acids in length or longer, 45 amino acids in length orlonger, 50 amino acids in length or longer, 55 amino acids in length orlonger, or 60 amino acids in length or longer.

Embodiment 3. The humanized antibody or binding fragment thereof ofEmbodiment 2, wherein the ultralong CDR3 is 35 amino acids in length orlonger.

Embodiment 4. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the ultralong CDR3 comprises 3 or more cysteineresidues, 4 or more cysteine residues, 5 or more cysteine residues, 6 ormore cysteine residues, 7 or more cysteine residues, 8 or more cysteineresidues, 9 or more cysteine residues, 10 or more cysteine residues, 11or more cysteine residues, or 12 or more cysteine residues.

Embodiment 5. The humanized antibody or binding fragment thereof ofEmbodiment 4, wherein the ultralong CDR3 comprises 3 or more cysteineresidues.

Embodiment 6. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the antibodies or binding fragments thereofcomprise a cysteine motif.

Embodiment 7. The humanized antibody or binding fragment thereof ofEmbodiment 6, wherein the cysteine motif is selected from the groupconsisting of:

(SEQ ID NO: 41) CX₁₀CX₅CX₅CXCX₇C,  (SEQ ID NO: 42) CX₁₀CX₆CX₅CXCX₁₅C,(SEQ ID NO: 43) CX₁₁CXCX₅C, (SEQ ID NO: 44) CX₁₁CX₅CX₅CXCX₇C,(SEQ ID NO: 45) CX₁₀CX₆CX₅CXCX₁₃C, (SEQ ID NO: 46) CX₁₀CX₅CXCX₄CX₈C,(SEQ ID NO: 47) CX₁₀CX₆CX₆CXCX₇C,  (SEQ ID NO: 48) CX₁₀CX₄CX₇CXCX₈C,(SEQ ID NO: 49) CX₁₀CX₄CX₇CXCX₇C, (SEQ ID NO: 50) CX₁₃CX₈CX₈C,(SEQ ID NO: 51) CX₁₀CX₆CX₅CXCX₇C, (SEQ ID NO: 52) CX₁₀CX₅CX₅C,(SEQ ID NO: 53) CX₁₀CX₅CX₆CXCX₇C,  (SEQ ID NO: 54) CX₁₀CX₆CX₅CX₇CX₈C,(SEQ ID NO: 55) CX₉CX₇CX₅CXCX₇C,  (SEQ ID NO: 56) CX₁₀CX₆CX₅CXCX₈C,(SEQ ID NO: 57) CX₁₀CXCX₄CX₅CX₁₁C,  (SEQ ID NO: 58)CX₇CX₃CX₆CX₅CXCX₅CX₁₀C, (SEQ ID NO: 59) CX₁₀CXCX₄CX₅CXCX₂CX₃C, (SEQ ID NO: 60) CX₁₆CX₅CXC, (SEQ ID NO: 61) CX₆CX₄CXCX₄CX₅C, (SEQ ID NO: 62) CX₁₁CX₄CX₅CX₆CX₃C, (SEQ ID NO: 63) CX₈CX₂CX₆CX₅C,(SEQ ID NO: 64) CX₁₀CX₅CX₅CXCX₁₀C, (SEQ ID NO: 65) CX₁₀CXCX₆CX₄CXC, (SEQ ID NO: 66) CX₁₀CX₅CX₅CXCX₂C, (SEQ ID NO: 67) CX₁₄CX₂CX₃CXCXC,(SEQ ID NO: 68) CX₁₅CX₅CXC, (SEQ ID NO: 69) CX₄CX₆CX₈CX₂CX₁₁C, (SEQ ID NO: 70) CX₆CX₄CX₅CX₅CX₁₂C, (SEQ ID NO: 71)CX₇CX₃CXCXCX₄CX₅CX₉C,  (SEQ ID NO: 72) CX₁₀CX₆CX₅C, (SEQ ID NO: 73)CX₇CX₃CX₅CX₅CX₉C,  (SEQ ID NO: 74) CX₇CX₅CXCX₂C,  (SEQ ID NO: 75)CX₁₀CXCX₆C,  (SEQ ID NO: 76) CX₁₀CX₃CX₃CX₅CX₇CXCX₆C,  (SEQ ID NO: 77)CX₁₀CX₄CX₅CX₁₂CX₂C,  (SEQ ID NO: 78) CX₁₂CX₄CX₅CXCXCX₉CX₃C, (SEQ ID NO: 79) CX₁₂CX₄CX₅CX₁₂CX₂C,  (SEQ ID NO: 80) CX₁₀CX₆CX₅CXCX₁₁C, (SEQ ID NO: 81) CX₁₆CX₅CXCXCX₁₄C,  (SEQ ID NO: 82) CX₁₀CX₅CXCX₈CX₆C, (SEQ ID NO: 83) CX₁₂CX₄CX₅CX₈CX₂C, (SEQ ID NO: 84) CX₁₂CX₅CX₅CXCX₈C, (SEQ ID NO: 85) CX₁₀CX₆CX₅CXCX₄CXCX₉C, (SEQ ID NO: 86)CX₁₁CX₄CX₅CX₈CX₂C,  (SEQ ID NO: 87) CX₁₀CX₆CX₅CX₈CX₂C, (SEQ ID NO: 88)CX₁₀CX₆CX₅CXCX₈C,  (SEQ ID NO: 89) CX₁₀CX₆CX₅CXCX₃CX₈CX₂C,(SEQ ID NO: 90) CX₁₀CX₆CX₅CX₃CX₈C,  (SEQ ID NO: 91)CX₁₀CX₆CX₅CXCX₂CX₆CX₅C, (SEQ ID NO: 92) CX₇CX₆CX₃CX₃CX₉C, (SEQ ID NO: 93) CX₉CX₈CX₅CX₆CX₅C, (SEQ ID NO: 94)CX₁₀CX₂CX₂CX₇CXCX₁₁CX₅C,  and  (SEQ ID NO: 95) CX₁₀CX₆CX₅CXCX₂CX₈CX₄C.

Embodiment 8. The humanized antibody or binding fragment thereof ofEmbodiment 6, wherein the cysteine motif is selected from the groupconsisting of:

(SEQ ID NO: 96) CCX₃CXCX₃CX₂CCXCX₅CX₉CX₅CXC,  (SEQ ID NO: 97)CX₆CX₂CX₅CX₄CCXCX₄CX₆CXC,  (SEQ ID NO: 98) CX₇CXCX₅CX₄CCCX₄CX₆CXC,(SEQ ID NO: 99) CX₉CX₃CXCX₂CXCCCX₆CX₄C,  (SEQ ID NO: 100)CX₅CX₃CXCX₄CX₄CCX₁₀CX₂CC,  (SEQ ID NO: 101) CX₅CXCX₁CXCX₃CCX₃CX₄CX₁₀C,(SEQ ID NO: 102) CX₉CCCX₃CX₄CCCX₅CX₆C,  (SEQ ID NO: 103)CCX₈CX₅CX₄CX₃CX₄CCXCX₁C, (SEQ ID NO: 104) CCX₆CCX₅CCCX₄CX₄CX₁₂C,(SEQ ID NO: 105) CX₆CX₂CX₃CCCX₄CX₅CX₃CX₃C,  (SEQ ID NO: 106)CX₃CX₅CX₆CX₄CCXCX₅CX₄CXC,  (SEQ ID NO: 107) CX₄CX₄CCX₄CX₄CXCX₁₁CX₂CXC,(SEQ ID NO: 108) CX₅CX₂CCX₅CX₄CCX₃CCX₇C,  (SEQ ID NO: 109)CX₅CX₅CX₃CX₂CXCCX₄CX₇CXC, (SEQ ID NO: 110) CX₃CX₇CX₃CX₄CCXCX₂CX₅CX₂C,(SEQ ID NO: 111) CX₉CX₃CXCX₄CCX₅CCCX₆C,  (SEQ ID NO: 112)CX₉CX₃CXCX₂CXCCX₆CX₃CX₃C, (SEQ ID NO: 113) CX₈CCXCX₃CCX₃CXCX₃CX₄C,(SEQ ID NO: 114) CX₉CCX₄CX₂CXCCXCX₄CX₃C,  (SEQ ID NO: 115)CX₁₀CXCX₃CX₂CXCCX₄CX₅CXC, (SEQ ID NO: 116) CX₉CXCX₃CX₂CXCCX₄CX₅CXC,(SEQ ID NO: 117) CX₆CCXCX₅CX₄CCXCX₅CX₂C,  (SEQ ID NO: 118)CX₆CCXCX₃CXCCX₃CX₄CC, (SEQ ID NO: 119) CX₆CCXCX₃CXCX₂CXCX₄CX₈C,(SEQ ID NO: 120) CX₄CX₂CCX₃CXCX₄CCX₂CX₃C,  (SEQ ID NO: 121)CX₃CX₅CX₃CCCX₄CX₉C,  (SEQ ID NO: 122) CCX₉CX₃CXCCX₃CX₅C, (SEQ ID NO: 123) CX₉CX₂CX₃CX₄CCX₄CX₅C,  (SEQ ID NO: 124)CX₉CX₇CX₄CCXCX₇CX₃C,  (SEQ ID NO: 125) CX₉CX₃CCCX₁₀CX₂CX₃C, (SEQ ID NO: 126) CX₃CX₅CX₅CX₄CCX₁₀CX₆C,  (SEQ ID NO: 127)CX₉CX₅CX₄CCXCX₅CX₄C,  (SEQ ID NO: 128) CX₇CXCX₆CX₄CCCX₁₀C, (SEQ ID NO: 129) CX₈CX₂CX₄CCX₄CX₃CX₃C,  (SEQ ID NO: 130)CX₇CX₅CXCX₄CCX₇CX₄C,  (SEQ ID NO: 131) CX₁₁CX₃CX₄CCCX₈CX₂C, (SEQ ID NO: 132) CX₂CX₃CX₄CCX₄CX₅CX₁₅C,  (SEQ ID NO: 133)CX₉CX₅CX₄CCX₇C,  (SEQ ID NO: 134) CX₉CX₇CX₃CX₂CX₆C,  (SEQ ID NO: 135)CX₉CX₅CX₄CCX₁₄C, (SEQ ID NO: 136) CX₉CX₅CX₄CCX₉C, (SEQ ID NO: 137)CX₉CX₆CX₄CCXC, (SEQ ID NO: 138) CX₅CCX₇CX₄CX₁₂,  (SEQ ID NO: 139)CX₁₀CX₃CX₄CCX₄C, (SEQ ID NO: 140) CX₉CX₄CCX₅CX₄C,  (SEQ ID NO: 141)CX₁₀CX₃CX₄CX₇CXC, (SEQ ID NO: 142) CX₇CX₇CX₂CX₂CX₃C,  (SEQ ID NO: 143)CX₉CX₄CX₄CCX₆C, (SEQ ID NO: 144) CX₇CXCX₃CXCX₆C,  (SEQ ID NO: 145)CX₇CXCX₄CXCX₄C, (SEQ ID NO: 146) CX₉CX₅CX₄C,  (SEQ ID NO: 147)CX₃CX₆CX₉C,  (SEQ ID NO: 148) CX₁₀CXCX₄C,  (SEQ ID NO: 149) CX₁₀CCX₄C, (SEQ ID NO: 150) CX₁₅C,  (SEQ ID NO: 151) CX₁₀C,  and  (SEQ ID NO: 152)CX₉C.

Embodiment 9. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the ultralong CDR3 comprises 2 to 6 disulfidebonds.

Embodiment 10. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the ultralong CDR3 comprises SEQ ID NO: 40 or aderivative thereof.

Embodiment 11. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the ultralong CDR3 comprises amino acid residues3-6 of any of one SEQ ID NO: 1-4.

Embodiment 12. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the ultralong CDR3 comprises a non-human DH or aderivative thereof.

Embodiment 13. The humanized antibody or binding fragment thereof ofEmbodiment 12, wherein the non-human DH is SEQ ID NO: 5, SEQ ID NO: 6,SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11,or SEQ ID NO: 12.

Embodiment 14. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the ultralong CDR3 comprises a JH sequence or aderivative thereof.

Embodiment 15. The humanized antibody or binding fragment thereof ofEmbodiment 14, wherein the JH sequence is SEQ ID NO: 13, SEQ ID NO: 14,SEQ ID NO: 15, SEQ ID NO: 16, or SEQ ID NO: 17.

Embodiment 16. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the ultralong CDR3 comprises: a non-human VHsequence or a derivative thereof; a non-human DH sequence or aderivative thereof; and/or a JH sequence or derivative thereof.

Embodiment 17. The humanized antibody or binding fragment thereof ofEmbodiment 16, wherein the ultralong CDR3 comprises an additional aminoacid sequence comprising two to six amino acid residues or morepositioned between the VH sequence and the DH sequence.

Embodiment 18. The humanized antibody or binding fragment thereof ofEmbodiment 17, wherein the additional amino acid sequence is selectedfrom the group consisting of: IR, IF, SEQ ID NO: 18, SEQ ID NO: 19, SEQID NO: 20 or SEQ ID NO: 21.

Embodiment 19. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the ultralong CDR3 comprises a sequence derivedfrom or based on SEQ ID NO: 22, SEQ ID NO: 23, SEQ ID NO: 24, SEQ ID NO:25, SEQ ID NO: 26, SEQ ID NO: 27, or SEQ ID NO: 28.

Embodiment 20. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the ultralong CDR3 comprises a non-bovine sequenceor a non-antibody sequence.

Embodiment 21. The humanized antibody or binding fragment thereof ofEmbodiment 20, wherein the non-antibody sequence is a syntheticsequence.

Embodiment 22. The humanized antibody or binding fragment thereof ofEmbodiment 20, wherein the non-antibody sequence is a cytokine sequence,a lymphokine sequence, a chemokine sequence, a growth factor sequence, ahormone sequence, or a toxin sequence.

Embodiment 23. The humanized antibody or binding fragment thereof ofEmbodiment 20, wherein the non-antibody sequence is an IL-8 sequence, anIL-21 sequence, an SDF-1 (alpha) sequence, a somatostatin sequence, achlorotoxin sequence, a Pro-TxII sequence, or a ziconotide sequence.

Embodiment 24. The humanized antibody or binding fragment thereof ofEmbodiment 20, wherein the non-antibody sequence is any one of SEQ IDNOS: 475-481.

Embodiment 25. The humanized antibody or binding fragment thereof ofEmbodiment 20, wherein the non-antibody sequence replaces at least aportion of the ultralong CDR3.

Embodiment 26. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the ultralong CDR3 comprises a X¹X²X³X⁴X⁵ motif,wherein X¹ is threonine (T), glycine (G), alanine (A), serine (S), orvaline (V), wherein X² is serine (S), threonine (T), proline (P),isoleucine (I), alanine (A), valine (V), or asparagine (N), wherein X³is valine (V), alanine (A), threonine (T), or aspartic acid (D), whereinX⁴ is histidine (H), threonine (T), arginine (R), tyrosine (Y),phenylalanine (F), or leucine (L), and wherein X⁵ is glutamine (Q).

Embodiment 27. The humanized antibody or binding fragment thereof ofEmbodiment 26, wherein the X¹X²X³X⁴X⁵ motif is TTVHQ (SEQ ID NO: 153),TSVHQ (SEQ ID NO: 154), SSVTQ (SEQ ID NO: 155), STVHQ (SEQ ID NO: 156),ATVRQ (SEQ ID NO: 157), TTVYQ (SEQ ID NO: 158), SPVHQ (SEQ ID NO: 159),ATVYQ (SEQ ID NO: 160), TAVYQ (SEQ ID NO: 161), TNVHQ (SEQ ID NO: 162),ATVHQ (SEQ ID NO: 163), STVYQ (SEQ ID NO: 164), TIVHQ (SEQ ID NO: 165),AIVYQ (SEQ ID NO: 166), TTVFQ (SEQ ID NO: 167), AAVFQ (SEQ ID NO: 168),GTVHQ (SEQ ID NO: 169), ASVHQ (SEQ ID NO: 170), TAVFQ (SEQ ID NO: 171),ATVFQ (SEQ ID NO: 172), AAAHQ (SEQ ID NO: 173), VVVYQ (SEQ ID NO: 174),GTVFQ (SEQ ID NO: 175), TAVHQ (SEQ ID NO: 176), ITVHQ (SEQ ID NO: 177),ITAHQ (SEQ ID NO: 178), VTVHQ (SEQ ID NO: 179); AAVHQ (SEQ ID NO: 180),GTVYQ (SEQ ID NO: 181), TTVLQ (SEQ ID NO: 182), TTTHQ (SEQ ID NO: 183),or TTDYQ (SEQ ID NO: 184).

Embodiment 28. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the ultralong CDR3 comprises a CX¹X²X³X⁴X⁵ motif.

Embodiment 29. The humanized antibody or binding fragment thereof ofEmbodiment 28, wherein the CX¹X²X³X⁴X⁵ motif is CTTVHQ (SEQ ID NO: 185),CTSVHQ (SEQ ID NO: 186), CSSVTQ (SEQ ID NO: 187), CSTVHQ (SEQ ID NO:188), CATVRQ (SEQ ID NO: 189), CTTVYQ (SEQ ID NO: 190), CSPVHQ (SEQ IDNO: 191), CATVYQ (SEQ ID NO: 192), CTAVYQ (SEQ ID NO: 193), CTNVHQ (SEQID NO: 194), CATVHQ (SEQ ID NO: 195), CSTVYQ (SEQ ID NO: 196), CTIVHQ(SEQ ID NO: 197), CAIVYQ (SEQ ID NO: 198), CTTVFQ (SEQ ID NO: 199),CAAVFQ (SEQ ID NO: 200), CGTVHQ (SEQ ID NO: 201), CASVHQ (SEQ ID NO:202), CTAVFQ (SEQ ID NO: 203), CATVFQ (SEQ ID NO: 204), CAAAHQ (SEQ IDNO: 205), CVVVYQ (SEQ ID NO: 206), CGTVFQ (SEQ ID NO: 207), CTAVHQ (SEQID NO: 208), CITVHQ (SEQ ID NO: 209), CITAHQ (SEQ ID NO: 210), CVTVHQ(SEQ ID NO: 211); CAAVHQ (SEQ ID NO: 212), CGTVYQ (SEQ ID NO: 213),CTTVLQ (SEQ ID NO: 214), CTTTHQ (SEQ ID NO: 215), or CTTDYQ (SEQ ID NO:216).

Embodiment 30. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the ultralong CDR3 comprises a (X^(a)X^(b))_(z)motif, wherein X^(a) is any amino acid residue, X^(b) is an aromaticamino acid selected from the group consisting of: tyrosine (Y),phenylalanine (F), tryptophan (W), and histidine (H), and wherein z is1-4.

Embodiment 31. The humanized antibody or binding fragment thereof ofEmbodiment 30, wherein the (X^(a)X^(b))_(z) motif is CYTYNYEF (SEQ IDNO: 217), HYTYTYDF (SEQ ID NO: 218), HYTYTYEW (SEQ ID NO: 219), KHRYTYEW(SEQ ID NO: 220), NYIYKYSF (SEQ ID NO: 221), PYIYTYQF (SEQ ID NO: 222),SFTYTYEW (SEQ ID NO: 223), SYIYIYQW (SEQ ID NO: 224), SYNYTYSW (SEQ IDNO: 225), SYSYSYEY (SEQ ID NO: 226), SYTYNYDF (SEQ ID NO: 227), SYTYNYEW(SEQ ID NO: 228), SYTYNYQF (SEQ ID NO: 229), SYVWTHNF (SEQ ID NO: 230),TYKYVYEW (SEQ ID NO: 231), TYTYTYEF (SEQ ID NO: 232), TYTYTYEW (SEQ IDNO: 233), VFTYTYEF (SEQ ID NO: 234), AYTYEW (SEQ ID NO: 235), DYIYTY(SEQ ID NO: 236), IHSYEF (SEQ ID NO: 237), SFTYEF (SEQ ID NO: 238),SHSYEF (SEQ ID NO: 239), THTYEF (SEQ ID NO: 240), TWTYEF (SEQ ID NO:241), TYNYEW (SEQ ID NO: 242), TYSYEF (SEQ ID NO: 243), TYSYEH (SEQ IDNO: 244), TYTYDF (SEQ ID NO: 245), TYTYEF (SEQ ID NO: 246), TYTYEW (SEQID NO: 247), AYEF (SEQ ID NO: 248), AYSF (SEQ ID NO: 249), AYSY (SEQ IDNO: 250), CYSF (SEQ ID NO: 251), DYTY (SEQ ID NO: 252), KYEH (SEQ ID NO:253), KYEW (SEQ ID NO: 254), MYEF (SEQ ID NO: 255), NWIY (SEQ ID NO:256), NYDY (SEQ ID NO: 257), NYQW (SEQ ID NO: 258), NYSF (SEQ ID NO:259), PYEW (SEQ ID NO: 260), RYNW (SEQ ID NO: 261), RYTY (SEQ ID NO:262), SYEF (SEQ ID NO: 263), SYEH (SEQ ID NO: 264), SYEW (SEQ ID NO:265), SYKW (SEQ ID NO: 266), SYTY (SEQ ID NO: 267), TYDF (SEQ ID NO:268), TYEF (SEQ ID NO: 269), TYEW (SEQ ID NO: 270), TYQW (SEQ ID NO:271), TYTY (SEQ ID NO: 272), or VYEW (SEQ ID NO: 273).

Embodiment 32. The humanized antibody or binding fragment thereof ofEmbodiment 30, wherein the (X^(a)X^(b))_(z) motif is YXYXYX.

Embodiment 33. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the ultralong CDR3 comprises a X¹X²X³X⁴X⁵X_(n)motif, wherein X₁ is threonine (T), glycine (G), alanine (A), serine(S), or valine (V), wherein X₂ is serine (S), threonine (T), proline(P), isoleucine (I), alanine (A), valine (V), or asparagine (N), whereinX₃ is valine (V), alanine (A), threonine (T), or aspartic acid (D),wherein X₄ is histidine (H), threonine (T), arginine (R), tyrosine (Y),phenylalanine (F), or leucine (L), wherein X₅ is glutamine (Q), andwherein n is 27-54.

Embodiment 34. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the ultralong CDR3 comprises X_(n)(X^(a)X^(b))_(z)motif, wherein X^(a) is any amino acid residue, X^(b) is an aromaticamino acid selected from the group consisting of: tyrosine (Y),phenylalanine (F), tryptophan (W), and histidine (H), wherein n is27-54, and wherein z is 1-4.

Embodiment 35. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the ultralong CDR3 comprises aX¹X²X³X⁴X⁵X_(n)(X^(a)X^(b))_(z) motif, wherein X¹ is threonine (T),glycine (G), alanine (A), serine (S), or valine (V), wherein X² isserine (S), threonine (T), proline (P), isoleucine (I), alanine (A),valine (V), or asparagine (N), wherein X³ is valine (V), alanine (A),threonine (T), or aspartic acid (D), wherein X⁴ is histidine (H),threonine (T), arginine (R), tyrosine (Y), phenylalanine (F), or leucine(L), and wherein X⁵ is glutamine (Q), wherein X^(a) is any amino acidresidue, X^(b) is an aromatic amino acid selected from the groupconsisting of: tyrosine (Y), phenylalanine (F), tryptophan (W), andhistidine (H), wherein n is 27-54, and wherein z is 1-4.

Embodiment 36. The humanized antibody or binding fragment thereof ofEmbodiment 35, wherein the X¹X²X³X⁴X⁵ motif is TTVHQ (SEQ ID NO: 153) orTSVHQ (SEQ ID NO: 154), and wherein the (X^(a)X^(b))_(z) motif isYXYXYX.

Embodiment 37. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the ultralong CDR3 comprises: a CX¹X²X³X⁴X⁵ motif,wherein X¹ is threonine (T), glycine (G), alanine (A), serine (S), orvaline (V), wherein X² is serine (S), threonine (T), proline (P),isoleucine (I), alanine (A), valine (V), or asparagine (N), wherein X³is valine (V), alanine (A), threonine (T), or aspartic acid (D), whereinX⁴ is histidine (H), threonine (T), arginine (R), tyrosine (Y),phenylalanine (F), or leucine (L), and wherein X⁵ is glutamine (Q), acysteine motif selected from the group consisting of: CX₁₀CX₅CX₅CXCX₇C(SEQ ID NO: 41), CX₁₀CX₆CX₅CXCX₁₅C (SEQ ID NO: 42), CX₁₁CXCX₅C (SEQ IDNO: 43), CX₁₁CX₅CX₅CXCX₇C (SEQ ID NO: 44), CX₁₀CX₆CX₅CXCX₁₃C (SEQ ID NO:45), CX₁₀CX₅CXCX₄CX₈C (SEQ ID NO: 46), CX₁₀CX₆CX₆CXCX₇C (SEQ ID NO: 47),CX₁₀CX₄CX₇CXCX₈C (SEQ ID NO: 48), CX₁₀CX₄CX₇CXCX₇C (SEQ ID NO: 49),CX₁₃CX₈CX₈C (SEQ ID NO: 50), CX₁₀CX₆CX₅CXCX₇C (SEQ ID NO: 51),CX₁₀CX₅CX₅C (SEQ ID NO: 52), CX₁₀CX₅CX₆CXCX₇C (SEQ ID NO: 53),CX₁₀CX₆CX₅CX₇CX₉C (SEQ ID NO: 54), CX₉CX₇CX₅CXCX₇C (SEQ ID NO: 55),CX₁₀CX₆CX₅CXCX₉C (SEQ ID NO: 56), CX₁₀CXCX₄CX₅CX₁₁C (SEQ ID NO: 57),CX₇CX₃CX₆CX₅CXCX₅CX₁₀C (SEQ ID NO: 58), CX₁₀CXCX₄CX₅CXCX₂CX₃C (SEQ IDNO: 59), CX₁₆CX₅CXC (SEQ ID NO: 60), CX₆CX₄CXCX₄CX₅C (SEQ ID NO: 61),CX₁₁CX₄CX₅CX₆CX₃C (SEQ ID NO: 62), CX₈CX₂CX₆CX₅C (SEQ ID NO: 63),CX₁₀CX₅CX₅CXCX₁₀C (SEQ ID NO: 64), CX₁₀CXCX₆CX₄CXC (SEQ ID NO: 65),CX₁₀CX₅CX₅CXCX₂C (SEQ ID NO: 66), CX₁₄CX₂CX₃CXCXC (SEQ ID NO: 67),CX₁₅CX₅CXC (SEQ ID NO: 68), CX₄CX₆CX₉CX₂CX₁₁C (SEQ ID NO: 69),CX₆CX₄CX₅CX₅CX₁₂C (SEQ ID NO: 70), CX₇CX₃CXCXCX₄CX₅CX₉C (SEQ ID NO: 71),CX₁₀CX₆CX₅C (SEQ ID NO: 72), CX₇CX₃CX₅CX₅CX₉C (SEQ ID NO: 73),CX₇CX₅CXCX₂C (SEQ ID NO: 74), CX₁₀CXCX₆C (SEQ ID NO: 75),CX₁₀CX₃CX₃CX₅CX₇CXCX₆C (SEQ ID NO: 76), CX₁₀CX₄CX₅CX₁₂CX₂C (SEQ ID NO:77), CX₁₂CX₄CX₅CXCXCX₉CX₃C (SEQ ID NO: 78), CX₁₂CX₄CX₅CX₁₂CX₂C (SEQ IDNO: 79), CX₁₀CX₆CX₅CXCX₁₁C (SEQ ID NO: 80), CX₁₆CX₅CXCXCX₁₄C (SEQ ID NO:81), CX₁₀CX₅CXCX₈CX₆C (SEQ ID NO: 82), CX₁₂CX₄CX₅CX₈CX₂C (SEQ ID NO:83), CX₁₂CX₅CX₅CXCX₈C (SEQ ID NO: 84), CX₁₀CX₆CX₅CXCX₄CXCX₉C (SEQ ID NO:85), CX₁₁CX₄CX₅CX₈CX₂C (SEQ ID NO: 86), CX₁₉CX₆CX₅CX₈CX₂C (SEQ ID NO:87), CX₁₀CX₆CX₅CXCX₈C (SEQ ID NO: 88), CX₁₉CX₆CX₅CXCX₃CX₈CX₂C (SEQ IDNO: 89), CX₁₀CX₆CX₅CX₃CX₈C (SEQ ID NO: 90), CX₁₀CX₆CX₅CXCX₂CX₆CX₅C (SEQID NO: 91), CX₇CX₆CX₃CX₃CX₉C (SEQ ID NO: 92), CX₉CX₈CX₅CX₆CX₅C (SEQ IDNO: 93), CX₁₀CX₂CX₂CX₇CXCX₁₁CX₅C (SEQ ID NO: 94), andCX₁₀CX₆CX₅CXCX₂CX₈CX₄C (SEQ ID NO: 95); and a (X^(a)X^(b))_(z) motif,wherein X^(a) is any amino acid residue, X^(b) is an aromatic amino acidselected from the group consisting of: tyrosine (Y), phenylalanine (F),tryptophan (W), and histidine (H), and wherein z is 1-4.

Embodiment 38. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the ultralong CDR3 comprises: a CX¹X²X³X⁴X⁵motif,wherein X¹ is threonine (T), glycine (G), alanine (A), serine (S), orvaline (V), wherein X² is serine (S), threonine (T), proline (P),isoleucine (I), alanine (A), valine (V), or asparagine (N), wherein X³is valine (V), alanine (A), threonine (T), or aspartic acid (D), whereinX⁴ is histidine (H), threonine (T), arginine (R), tyrosine (Y),phenylalanine (F), or leucine (L), and wherein X⁵ is glutamine (Q); acysteine motif selected from the group consisting of: wherein thecysteine motif is selected from the group consisting of:CCX₃CXCX₃CX₂CCXCX₅CX₉CX₅CXC (SEQ ID NO: 96), CX₆CX₂CX₅CX₄CCXCX₄CX₆CXC(SEQ ID NO: 97), CX₇CXCX₅CX₄CCCX₄CX₆CXC (SEQ ID NO: 98),CX₉CX₃CXCX₂CXCCCX₆CX₄C (SEQ ID NO: 99), CX₅CX₃CXCX₄CX₄CCX₁₀CX₂CC (SEQ IDNO: 100), CX₅CXCX₁CXCX₃CCX₃CX₄CX₁₀C (SEQ ID NO: 101),CX₉CCCX₃CX₄CCCX₅CX₆C (SEQ ID NO: 102), CCX₈CX₅CX₄CX₃CX₄CCXCX₁C (SEQ IDNO: 103), CCX₆CCX₅CCCX₄CX₄CX₁₂C (SEQ ID NO: 104),CX₆CX₂CX₃CCCX₄CX₅CX₃CX₃C (SEQ ID NO: 105), CX₃CX₅CX₆CX₄CCXCX₅CX₄CXC (SEQID NO: 106), CX₄CX₄CCX₄CX₄CXCX₁₁CX₂CXC (SEQ ID NO: 107),CX₅CX₂CCX₅CX₄CCX₃CCX₇C (SEQ ID NO: 108), CX₅CX₅CX₃CX₂CXCCX₄CX₇CXC (SEQID NO: 109), CX₃CX₇CX₃CX₄CCXCX₂CX₅CX₂C (SEQ ID NO: 110),CX₉CX₃CXCX₄CCX₅CCCX₆C (SEQ ID NO: 111), CX₉CX₃CXCX₂CXCCX₆CX₃CX₃C (SEQ IDNO: 112), CX₈CCXCX₃CCX₃CXCX₃CX₄C (SEQ ID NO: 113),CX₉CCX₄CX₂CXCCXCX₄CX₃C (SEQ ID NO: 114), CX₁₀CXCX₃CX₂CXCCX₄CX₅CXC (SEQID NO: 115), CX₉CXCX₃CX₂CXCCX₄CX₅CXC (SEQ ID NO: 116),CX₆CCXCX₅CX₄CCXCX₅CX₂C (SEQ ID NO: 117), CX₆CCXCX₃CXCCX₃CX₄CC (SEQ IDNO: 118), CX₆CCXCX₃CXCX₂CXCX₄CX₈C (SEQ ID NO: 119),CX₄CX₂CCX₃CXCX₄CCX₂CX₃C (SEQ ID NO: 120), CX₃CX₅CX₃CCCX₄CX₉C (SEQ ID NO:121), CCX₉CX₃CXCCX₃CX₅C (SEQ ID NO: 122), CX₉CX₂CX₃CX₄CCX₄CX₅C (SEQ IDNO: 123), CX₉CX₇CX₄CCXCX₇CX₃C (SEQ ID NO: 124), CX₉CX₃CCCX₁₀CX₂CX₃C (SEQID NO: 125), CX₃CX₅CX₅CX₄CCX₁₀CX₆C (SEQ ID NO: 126), CX₉CX₅CX₄CCXCX₅CX₄C(SEQ ID NO: 127), CX₇CXCX₆CX₄CCCX₁₀C (SEQ ID NO: 128),CX₈CX₂CX₄CCX₄CX₃CX₃C (SEQ ID NO: 129), CX₇CX₅CXCX₄CCX₇CX₄C (SEQ ID NO:130), CX₁₁CX₃CX₄CCCX₈CX₂C (SEQ ID NO: 131), CX₂CX₃CX₄CCX₄CX₅CX₁₅C (SEQID NO: 132), CX₉CX₅CX₄CCX₇C (SEQ ID NO: 133), CX₉CX₇CX₃CX₂CX₆C (SEQ IDNO: 134), CX₉CX₅CX₄CCX₁₄C (SEQ ID NO: 135), CX₉CX₅CX₄CCX₈C (SEQ ID NO:136), CX₉CX₆CX₄CCXC (SEQ ID NO: 137), CX₅CCX₇CX₄CX₁₂ (SEQ ID NO: 138),CX₁₀CX₃CX₄CCX₄C (SEQ ID NO: 139), CX₉CX₄CCX₅CX₄C (SEQ ID NO: 140),CX₁₀CX₃CX₄CX₇CXC (SEQ ID NO: 141), CX₇CX₇CX₂CX₂CX₃C (SEQ ID NO: 142),CX₉CX₄CX₄CCX₆C (SEQ ID NO: 143), CX₇CXCX₃CXCX₆C (SEQ ID NO: 144),CX₇CXCX₄CXCX₄C (SEQ ID NO: 145), CX₉CX₅CX₄C (SEQ ID NO: 146), CX₃CX₆CX₈C(SEQ ID NO: 147), CX₁₀CXCX₄C (SEQ ID NO: 148), CX₁₀CCX₄C (SEQ ID NO:149), CX₁₅C (SEQ ID NO: 150), CX₁₀C (SEQ ID NO: 151), and CX₉C (SEQ IDNO: 152); and a (X^(a)X^(b))_(z) motif, wherein X^(a) is any amino acidresidue, X^(b) is an aromatic amino acid selected from the groupconsisting of: tyrosine (Y), phenylalanine (F), tryptophan (W), andhistidine (H), and wherein z is 1-4.

Embodiment 39. The humanized antibody or binding fragment thereof ofEmbodiment 20, wherein the ultralong CDR3 comprises an additionalsequence that is a linker.

Embodiment 40. The humanized antibody or binding fragment thereof ofEmbodiment 39, wherein the linker is linked to a C-terminus, aN-terminus, or both C-terminus and N-terminus of the non-antibodysequence.

Embodiment 41. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the ultralong CDR3 is a ruminant CDR3.

Embodiment 42. The humanized antibody or binding fragment thereof ofEmbodiment 41, wherein the ruminant is a cow.

Embodiment 43. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the humanized antibody or binding fragment thereofcomprises a human heavy chain germline sequence that is a VH4 familymember germline sequence.

Embodiment 44. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the humanized antibody or binding fragment thereofcomprises a VH4-34 germline sequence.

Embodiment 45. The humanized antibody or binding fragment thereof ofEmbodiment 44, wherein the humanized antibody or binding fragmentthereof comprises a human heavy chain germline sequence that is derivedfrom the VH4-34 germline sequence.

Embodiment 46. The humanized antibody or binding fragment thereof ofEmbodiment 45, wherein the VH4-34 germline sequence comprises a CDR1comprising a Gly31Asp and Tyr32Lys substitution based on Kabatnumbering.

Embodiment 47. The humanized antibody or binding fragment thereof ofEmbodiment 45, wherein the VH4-34 germline sequence comprises a CDR2comprising a Glu50Ser substitution based on Kabat numbering.

Embodiment 48. The humanized antibody or binding fragment thereof ofEmbodiment 45, wherein the VH4-34 germline sequence comprises a CDR1comprising Ala23Thr, Val24Ala, Tyr25Ser, Gly27Phe, Phe29Leu, Gly31Asp,Tyr32Lys, Tyr33Ala, Trp34Val, and Ser35Gly substitutions, and a CDR2comprising Ile48Leu, Glu50Ser, Asn52Asp, His53Thr, Ser54Gly, Ser56Asn,and Asn58Gly substitutions, based on Kabat numbering.

Embodiment 49. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the humanized antibody or binding fragment thereofcomprises the amino acid sequence set forth in SEQ ID NO: 461, 462, 463,464, 465, 466, 467, 468, or 469.

Embodiment 50. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the humanized antibody or binding fragment thereofcomprises the amino acid sequence set forth in SEQ ID NO: 470.

Embodiment 51. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the humanized antibody or binding fragment thereofcomprises the amino acid sequence set forth in SEQ ID NO: 461, 462, 463,464, 465, 466, 467, 468, or 469; and the amino acid sequence set forthin SEQ ID NO: 470.

Embodiment 52. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the humanized antibody or binding fragment thereofcomprises the amino acid sequence set forth in SEQ ID NO: 461, 462, 463,464, 465, 466, 467, 468, or 469; the amino acid sequence set forth inSEQ ID NO: 470; and a peptide sequence, wherein the peptide sequence ispositioned between SEQ ID NO: 461, 462, 463, 464, 465, 466, 467, 468, or469, and SEQ ID NO: 470.

Embodiment 53. The humanized antibody or binding fragment thereof ofEmbodiment 52, wherein the peptide sequence is a bovine sequence, anon-bovine sequence, an antibody sequence, or a non-antibody sequence.

Embodiment 54. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the humanized antibody or binding fragment thereofcomprises a light chain variable region sequence that is a lambda lightchain variable region sequence.

Embodiment 55. The humanized antibody or binding fragment thereof ofEmbodiment 54, wherein the lambda light chain variable region sequenceis a bovine lambda light chain variable region sequence.

Embodiment 56. The humanized antibody or binding fragment thereof ofEmbodiment 54, wherein the lambda light chain variable region sequenceis a human lambda light chain variable region sequence.

Embodiment 57. The humanized antibody or binding fragment thereof ofEmbodiment 56, wherein the human lambda light chain variable regionsequence is a VL1-51 germline sequence.

Embodiment 58. The humanized antibody or binding fragment thereof ofEmbodiment 56, wherein the human lambda light chain variable regionsequence is derived from a VL1-51 germline sequence.

Embodiment 59. The humanized antibody or binding fragment thereof ofEmbodiment 58, wherein the VL1-51 germline sequence comprises a CDR1comprising Ile29Val and Asn32Gly substitution based on Kabat numbering.

Embodiment 60. The humanized antibody or binding fragment thereof ofEmbodiment 58, wherein the VL1-51 germline sequence comprises a CDR2comprising a substitution of DNN to GDT.

Embodiment 61. The humanized antibody or binding fragment thereof ofEmbodiment 58, wherein the VL1-51 germline sequence comprises a CDR2comprising a substitution of DNNKRP (SEQ ID NO: 471) to GDTSRA (SEQ IDNO: 472).

Embodiment 62. The humanized antibody or binding fragment thereof ofEmbodiment 58, wherein the VL1-51 germline sequence comprises a S2A,T5N, P8S, A12G, A13S, and P14L substitution based on Kabat numbering.

Embodiment 63. The humanized antibody or binding fragment thereof ofEmbodiment 58, wherein the VL1-51 germline sequence comprises a S2A,T5N, P8S, A12G, A13S, and P14L substitution based on Kabat numbering,and a CDR2 comprising a substitution of DNN to GDT.

Embodiment 64. The humanized antibody or binding fragment thereof ofEmbodiment 1, wherein the humanized antibody or binding fragment thereofcomprising the amino acid sequence set forth in SEQ ID NO: 440, 441,442, 443, or 444.

Embodiment 65. A polynucleotide encoding the humanized antibody orbinding fragment thereof of any one of Embodiments 1-64.

Embodiment 66. A polynucleotide encoding a humanized antibody or bindingfragment thereof that comprises an ultralong CDR3.

Embodiment 67. A polynucleotide encoding a humanized variable regionthat comprises an ultralong CDR3.

Embodiment 68. A vector comprising the polynucleotide of any one ofEmbodiments 65-67.

Embodiment 69. A host cell comprising the vector of Embodiment 68.

Embodiment 70. A nucleic acid library comprising a plurality ofpolynucleotides comprising sequences coding for humanized antibodies orbinding fragments thereof, wherein the antibodies or binding fragmentsthereof comprise an ultralong CDR3.

Embodiment 71. A library of humanized antibodies or binding fragmentsthereof, wherein the antibodies or binding fragments thereof comprise anultralong CDR3. In some embodiments, the humanized antibodies or bindingfragments thereof in the library comprise one or more human variableregion framework sequences.

Embodiment 72. The library of Embodiment 71, wherein the ultralong CDR3is 35 amino acids in length or longer, 40 amino acids in length orlonger, 45 amino acids in length or longer, 50 amino acids in length orlonger, 55 amino acids in length or longer, or 60 amino acids in lengthor longer.

Embodiment 73. The library of Embodiment 72, wherein the ultralong CDR3is 35 amino acids in length or longer.

Embodiment 74. The library of Embodiment 71, wherein the ultralong CDR3comprises 3 or more cysteine residues, 4 or more cysteine residues, 5 ormore cysteine residues, 6 or more cysteine residues, 7 or more cysteineresidues, 8 or more cysteine residues, 9 or more cysteine residues, 10or more cysteine residues, 11 or more cysteine residues, or 12 or morecysteine residues.

Embodiment 75. The library of Embodiment 74, wherein the ultralong CDR3comprises 3 or more cysteine residues.

Embodiment 76. The library of Embodiment 71, wherein the antibodies orbinding fragments thereof comprise a cysteine motif.

Embodiment 77. The library of Embodiment 76, wherein the cysteine motifis selected from the group consisting of:

(SEQ ID NO: 41) CX₁₀CX₅CX₅CXCX₇C, (SEQ ID NO: 42) CX₁₀CX₆CX₅CXCX₁₅C, (SEQ ID NO: 43) CX₁₁CXCX₅C, (SEQ ID NO: 44) CX₁₁CX₅CX₅CXCX₇C,(SEQ ID NO: 45) CX₁₀CX₆CX₅CXCX₁₃C, (SEQ ID NO: 46) CX₁₀CX₅CXCX₄CX₈C, (SEQ ID NO: 47) CX₁₀CX₆CX₆CXCX₇C, (SEQ ID NO: 48) CX₁₀CX₄CX₇CXCX₈C, (SEQ ID NO: 49) CX₁₀CX₄CX₇CXCX₇C, (SEQ ID NO: 50) CX₁₃CX₈CX₈C, (SEQ ID NO: 51) CX₁₀CX₆CX₅CXCX₇C,  (SEQ ID NO: 52) CX₁₀CX₅CX₅C, (SEQ ID NO: 53) CX₁₀CX₅CX₆CXCX₇C, (SEQ ID NO: 54) CX₁₀CX₆CX₅CX₇CX₈C, (SEQ ID NO: 55) CX₉CX₇CX₅CXCX₇C,  (SEQ ID NO: 56) CX₁₀CX₆CX₅CXCX₈C,(SEQ ID NO: 57) CX₁₀CXCX₄CX₅CX₁₁C,  (SEQ ID NO: 58)CX₇CX₃CX₆CX₅CXCX₅CX₁₀C, (SEQ ID NO: 59) CX₁₀CXCX₄CX₅CXCX₂CX₃C, (SEQ ID NO: 60) CX₁₆CX₅CXC, (SEQ ID NO: 61) CX₆CX₄CXCX₄CX₅C, (SEQ ID NO: 62) CX₁₁CX₄CX₅CX₆CX₃C, (SEQ ID NO: 63) CX₈CX₂CX₆CX₅C, (SEQ ID NO: 64) CX₁₀CX₅CX₅CXCX₁₀C, (SEQ ID NO: 65) CX₁₀CXCX₆CX₄CXC, (SEQ ID NO: 66) CX₁₀CX₅CX₅CXCX₂C, (SEQ ID NO: 67) CX₁₄CX₂CX₃CXCXC,(SEQ ID NO: 68) CX₁₅CX₅CXC, (SEQ ID NO: 69) CX₄CX₆CX₉CX₂CX₁₁C,(SEQ ID NO: 70) CX₆CX₄CX₅CX₅CX₁₂C, (SEQ ID NO: 71)CX₇CX₃CXCXCX₄CX₅CX₉C,  (SEQ ID NO: 72) CX₁₀CX₆CX₅C, (SEQ ID NO: 73)CX₇CX₃CX₅CX₅CX₉C,  (SEQ ID NO: 74) CX₇CX₅CXCX₂C,  (SEQ ID NO: 75)CX₁₀CXCX₆C,  (SEQ ID NO: 76) CX₁₀CX₃CX₃CX₅CX₇CXCX₆C,  (SEQ ID NO: 77)CX₁₀CX₄CX₅CX₁₂CX₂C,  (SEQ ID NO: 78) CX₁₂CX₄CX₅CXCXCX₉CX₃C, (SEQ ID NO: 79) CX₁₂CX₄CX₅CX₁₂CX₂C,  (SEQ ID NO: 80) CX₁₀CX₆CX₅CXCX₁₁C, (SEQ ID NO: 81) CX₁₆CX₅CXCXCX₁₄C,  (SEQ ID NO: 82) CX₁₀CX₅CXCX₈CX₆C, (SEQ ID NO: 83) CX₁₂CX₄CX₅CX₈CX₂C, (SEQ ID NO: 84) CX₁₂CX₅CX₅CXCX₈C, (SEQ ID NO: 85) CX₁₀CX₆CX₅CXCX₄CXCX₉C, (SEQ ID NO: 86)CX₁₁CX₄CX₅CX₈CX₂C, (SEQ ID NO: 87) CX₁₀CX₆CX₅CX₈CX₂C, (SEQ ID NO: 88)CX₁₀CX₆CX₅CXCX₈C,  (SEQ ID NO: 89) CX₁₀CX₆CX₅CXCX₃CX₈CX₂C,(SEQ ID NO: 90) CX₁₀CX₆CX₅CX₃CX₈C,  (SEQ ID NO: 91)CX₁₀CX₆CX₅CXCX₂CX₆CX₅C, (SEQ ID NO: 92) CX₇CX₆CX₃CX₃CX₉C, (SEQ ID NO: 93) CX₉CX₈CX₅CX₆CX₅C, (SEQ ID NO: 94)CX₁₀CX₂CX₂CX₇CXCX₁₁CX₅C,  and  (SEQ ID NO: 95) CX₁₀CX₆CX₅CXCX₂CX₈CX₄C.

Embodiment 78. The library of Embodiment 76, wherein the cysteine motifis selected from the group consisting of:

(SEQ ID NO: 96) CCX₃CXCX₃CX₂CCXCX₅CX₉CX₅CXC, (SEQ ID NO: 97)CX₆CX₂CX₅CX₄CCXCX₄CX₆CXC, (SEQ ID NO: 98) CX₇CXCX₅CX₄CCCX₄CX₆CXC, (SEQ ID NO: 99) CX₉CX₃CXCX₂CXCCCX₆CX₄C, (SEQ ID NO: 100)CX₅CX₃CXCX₄CX₄CCX₁₀CX₂CC, (SEQ ID NO: 101) CX₅CXCX₁CXCX₃CCX₃CX₄CX₁₀C, (SEQ ID NO: 102) CX₉CCCX₃CX₄CCCX₅CX₆C,  (SEQ ID NO: 103)CCX₈CX₅CX₄CX₃CX₄CCXCX₁C,  (SEQ ID NO: 104) CCX₆CCX₅CCCX₄CX₄CX₁₂C, (SEQ ID NO: 105) CX₆CX₂CX₃CCCX₄CX₅CX₃CX₃C, (SEQ ID NO: 106)CX₃CX₅CX₆CX₄CCXCX₅CX₄CXC,  (SEQ ID NO: 107) CX₄CX₄CCX₄CX₄CXCX₁₁CX₂CXC, (SEQ ID NO: 108) CX₅CX₂CCX₅CX₄CCX₃CCX₇C, (SEQ ID NO: 109)CX₅CX₅CX₃CX₂CXCCX₄CX₇CXC,  (SEQ ID NO: 110) CX₃CX₇CX₃CX₄CCXCX₂CX₅CX₂C, (SEQ ID NO: 111) CX₉CX₃CXCX₄CCX₅CCCX₆C, (SEQ ID NO: 112)CX₉CX₃CXCX₂CXCCX₆CX₃CX₃C,  (SEQ ID NO: 113) CX₈CCXCX₃CCX₃CXCX₃CX₄C,(SEQ ID NO: 114) CX₉CCX₄CX₂CXCCXCX₄CX₃C, (SEQ ID NO: 115)CX₁₀CXCX₃CX₂CXCCX₄CX₅CXC,  (SEQ ID NO: 116) CX₉CXCX₃CX₂CXCCX₄CX₅CXC, (SEQ ID NO: 117) CX₆CCXCX₅CX₄CCXCX₅CX₂C, (SEQ ID NO: 118)CX₆CCXCX₃CXCCX₃CX₄CC,  (SEQ ID NO: 119) CX₆CCXCX₃CXCX₂CXCX₄CX₈C, (SEQ ID NO: 120) CX₄CX₂CCX₃CXCX₄CCX₂CX₃C,  (SEQ ID NO: 121)CX₃CX₅CX₃CCCX₄CX₉C,  (SEQ ID NO: 122) CCX₉CX₃CXCCX₃CX₅C, (SEQ ID NO: 123) CX₉CX₂CX₃CX₄CCX₄CX₅C,  (SEQ ID NO: 124)CX₉CX₇CX₄CCXCX₇CX₃C,  (SEQ ID NO: 125) CX₉CX₃CCCX₁₀CX₂CX₃C, (SEQ ID NO: 126) CX₃CX₅CX₅CX₄CCX₁₀CX₆C, (SEQ ID NO: 127)CX₉CX₅CX₄CCXCX₅CX₄C,  (SEQ ID NO: 128) CX₇CXCX₆CX₄CCCX₁₀C,(SEQ ID NO: 129) CX₈CX₂CX₄CCX₄CX₃CX₃C,  (SEQ ID NO: 130)CX₇CX₅CXCX₄CCX₇CX₄C,  (SEQ ID NO: 131) CX₁₁CX₃CX₄CCCX₈CX₂C, (SEQ ID NO: 132) CX₂CX₃CX₄CCX₄CX₅CX₁₅C,  (SEQ ID NO: 133)CX₉CX₅CX₄CCX₇C,  (SEQ ID NO: 134) CX₉CX₇CX₃CX₂CX₆C, (SEQ ID NO: 135)CX₉CX₅CX₄CCX₁₄C,  (SEQ ID NO: 136) CX₉CX₆CX₄CCX₈C, (SEQ ID NO: 137)CX₉CX₆CX₄CCXC,  (SEQ ID NO: 138) CX₅CCX₇CX₄CX₁₂, (SEQ ID NO: 139)CX₁₀CX₃CX₄CCX₄C,  (SEQ ID NO: 140) CX₉CX₄CCX₅CX₄C, (SEQ ID NO: 141)CX₁₀CX₃CX₄CX₇CXC,  (SEQ ID NO: 142) CX₇CX₇CX₂CX₂CX₃C, (SEQ ID NO: 143)CX₉CX₄CX₄CCX₆C,  (SEQ ID NO: 144) CX₇CXCX₃CXCX₆C, (SEQ ID NO: 145)CX₇CXCX₄CXCX₄C,  (SEQ ID NO: 146) CX₉CX₅CX₄C,  (SEQ ID NO: 147)CX₃CX₆CX₈C,  (SEQ ID NO: 148) CX₁₀CXCX₄C,  (SEQ ID NO: 149) CX₁₀CCX₄C,(SEQ ID NO: 150) CX₁₅C,  (SEQ ID NO: 151) CX₁₀C,  and  (SEQ ID NO: 152)CX₉C.

Embodiment 79. The library of Embodiment 71, wherein the ultralong CDR3comprises 2 to 6 disulfide bonds.

Embodiment 80. The library of Embodiment 71, wherein the ultralong CDR3comprises SEQ ID NO: 40 or a derivative thereof.

Embodiment 81. The library of Embodiment 71, wherein the ultralong CDR3comprises amino acid residues 3-6 of any of one SEQ ID NO: 1-4.

Embodiment 82. The library of Embodiment 71, wherein the ultralong CDR3comprises a non-human DH or a derivative thereof.

Embodiment 83. The library of Embodiment 82, wherein the non-human DH isSEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9,SEQ ID NO: 10, SEQ ID NO: 11, or SEQ ID NO: 12

Embodiment 84. The library of Embodiment 71, wherein the ultralong CDR3comprises a JH sequence or a derivative thereof.

Embodiment 85. The library of Embodiment 84, wherein the JH sequence isSEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO: 15, SEQ ID NO: 16, or SEQ IDNO: 17.

Embodiment 86. The library of Embodiment 71, wherein the ultralong CDR3comprises: a non-human VH sequence or a derivative thereof; a non-humanDH sequence or a derivative thereof; and/or a JH sequence or derivativethereof.

Embodiment 87. The library of Embodiment 86, wherein the ultralong CDR3comprises an additional amino acid sequence comprising two to six aminoacid residues or more positioned between the VH sequence and the DHsequence.

Embodiment 88. The library of Embodiment 87, wherein the additionalamino acid sequence is selected from the group consisting of: IR, IF,SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20 or SEQ ID NO: 21.

Embodiment 89. The library of Embodiment 88, wherein the ultralong CDR3comprises a sequence derived from or based on SEQ ID NO: 22, SEQ ID NO:23, SEQ ID NO: 24, SEQ ID NO: 25, SEQ ID NO: 26, SEQ ID NO: 27, or SEQID NO: 28.

Embodiment 90. The library of Embodiment 71, wherein the ultralong CDR3comprises a non-bovine sequence or a non-antibody sequence.

Embodiment 91. The library of Embodiment 90, wherein the non-antibodysequence is a synthetic sequence.

Embodiment 92. The library of Embodiment 90, wherein the non-antibodysequence is a cytokine sequence, a lymphokine sequence, a chemokinesequence, a growth factor sequence, a hormone sequence, or a toxinsequence.

Embodiment 93. The library of Embodiment 90, wherein the non-antibodysequence is an IL-8 sequence, an IL-21 sequence, an SDF-1 (alpha)sequence, a somatostatin sequence, a chlorotoxin sequence, a Pro-TxIIsequence, or a ziconotide sequence.

Embodiment 94. The library of Embodiment 90, wherein the non-antibodysequence is any one of SEQ ID NOS: 475-481.

Embodiment 95. The library of Embodiment 71, wherein the ultralong CDR3comprises a X¹X²X³X⁴X⁵ motif, wherein X¹ is threonine (T), glycine (G),alanine (A), serine (S), or valine (V), wherein X² is serine (S),threonine (T), proline (P), isoleucine (I), alanine (A), valine (V), orasparagine (N), wherein X³ is valine (V), alanine (A), threonine (T), oraspartic acid (D), wherein X⁴ is histidine (H), threonine (T), arginine(R), tyrosine (Y), phenylalanine (F), or leucine (L), and wherein X⁵ isglutamine (Q).

Embodiment 96. The library of Embodiment 95, wherein the X¹X²X³X⁴X⁵motif is TTVHQ (SEQ ID NO: 153), TSVHQ (SEQ ID NO: 154), SSVTQ (SEQ IDNO: 155), STVHQ (SEQ ID NO: 156), ATVRQ (SEQ ID NO: 157), TTVYQ (SEQ IDNO: 158), SPVHQ (SEQ ID NO: 159), ATVYQ (SEQ ID NO: 160), TAVYQ (SEQ IDNO: 161), TNVHQ (SEQ ID NO: 162), ATVHQ (SEQ ID NO: 163), STVYQ (SEQ IDNO: 164), TIVHQ (SEQ ID NO: 165), AIVYQ (SEQ ID NO: 166), TTVFQ (SEQ IDNO: 167), AAVFQ (SEQ ID NO: 168), GTVHQ (SEQ ID NO: 169), ASVHQ (SEQ IDNO: 170), TAVFQ (SEQ ID NO: 171), ATVFQ (SEQ ID NO: 172), AAAHQ (SEQ IDNO: 173), VWYQ (SEQ ID NO: 174), GTVFQ (SEQ ID NO: 175), TAVHQ (SEQ IDNO: 176), ITVHQ (SEQ ID NO: 177), ITAHQ (SEQ ID NO: 178), VTVHQ (SEQ IDNO: 179); AAVHQ (SEQ ID NO: 180), GTVYQ (SEQ ID NO: 181), TTVLQ (SEQ IDNO: 182), TTTHQ (SEQ ID NO: 183), or TTDYQ (SEQ ID NO: 184).

Embodiment 97. The library of Embodiment 95, wherein the ultralong CDR3comprises a CX¹X²X³X⁴X⁵ motif.

Embodiment 98. The library of Embodiment 97, wherein the CX¹X²X³X⁴X⁵motif is CTTVHQ (SEQ ID NO: 185), CTSVHQ (SEQ ID NO: 186), CSSVTQ (SEQID NO: 187), CSTVHQ (SEQ ID NO: 188), CATVRQ (SEQ ID NO: 189), CTTVYQ(SEQ ID NO: 190), CSPVHQ (SEQ ID NO: 191), CATVYQ (SEQ ID NO: 192),CTAVYQ (SEQ ID NO: 193), CTNVHQ (SEQ ID NO: 194), CATVHQ (SEQ ID NO:195), CSTVYQ (SEQ ID NO: 196), CTIVHQ (SEQ ID NO: 197), CAIVYQ (SEQ IDNO: 198), CTTVFQ (SEQ ID NO: 199), CAAVFQ (SEQ ID NO: 200), CGTVHQ (SEQID NO: 201), CASVHQ (SEQ ID NO: 202), CTAVFQ (SEQ ID NO: 203), CATVFQ(SEQ ID NO: 204), CAAAHQ (SEQ ID NO: 205), CVVVYQ (SEQ ID NO: 206),CGTVFQ (SEQ ID NO: 207), CTAVHQ (SEQ ID NO: 208), CITVHQ (SEQ ID NO:209), CITAHQ (SEQ ID NO: 210), CVTVHQ (SEQ ID NO: 211); CAAVHQ (SEQ IDNO: 212), CGTVYQ (SEQ ID NO: 213), CTTVLQ (SEQ ID NO: 214), CTTTHQ (SEQID NO: 215), or CTTDYQ (SEQ ID NO: 216).

Embodiment 99. The humanized antibody or binding fragment thereof ofEmbodiment 71, wherein the ultralong CDR3 comprises a (X^(a)X^(b))_(z)motif, wherein X^(a) is any amino acid residue, X^(b) is an aromaticamino acid selected from the group consisting of: tyrosine (Y),phenylalanine (F), tryptophan (W), and histidine (H), and wherein z is1-4.

Embodiment 100. The humanized antibody or binding fragment thereof ofEmbodiment 99, wherein the (X^(a)X^(b))_(z) motif is CYTYNYEF (SEQ IDNO: 217), HYTYTYDF (SEQ ID NO: 218), HYTYTYEW (SEQ ID NO: 219), KHRYTYEW(SEQ ID NO: 220), NYIYKYSF (SEQ ID NO: 221), PYIYTYQF (SEQ ID NO: 222),SFTYTYEW (SEQ ID NO: 223), SYIYIYQW (SEQ ID NO: 224), SYNYTYSW (SEQ IDNO: 225), SYSYSYEY (SEQ ID NO: 226), SYTYNYDF (SEQ ID NO: 227), SYTYNYEW(SEQ ID NO: 228), SYTYNYQF (SEQ ID NO: 229), SYVWTHNF (SEQ ID NO: 230),TYKYVYEW (SEQ ID NO: 231), TYTYTYEF (SEQ ID NO: 232), TYTYTYEW (SEQ IDNO: 233), VFTYTYEF (SEQ ID NO: 234), AYTYEW (SEQ ID NO: 235), DYIYTY(SEQ ID NO: 236), IHSYEF (SEQ ID NO: 237), SFTYEF (SEQ ID NO: 238),SHSYEF (SEQ ID NO: 239), THTYEF (SEQ ID NO: 240), TWTYEF (SEQ ID NO:241), TYNYEW (SEQ ID NO: 242), TYSYEF (SEQ ID NO: 243), TYSYEH (SEQ IDNO: 244), TYTYDF (SEQ ID NO: 245), TYTYEF (SEQ ID NO: 246), TYTYEW (SEQID NO: 247), AYEF (SEQ ID NO: 248), AYSF (SEQ ID NO: 249), AYSY (SEQ IDNO: 250), CYSF (SEQ ID NO: 251), DYTY (SEQ ID NO: 252), KYEH (SEQ ID NO:253), KYEW (SEQ ID NO: 254), MYEF (SEQ ID NO: 255), NWIY (SEQ ID NO:256), NYDY (SEQ ID NO: 257), NYQW (SEQ ID NO: 258), NYSF (SEQ ID NO:259), PYEW (SEQ ID NO: 260), RYNW (SEQ ID NO: 261), RYTY (SEQ ID NO:262), SYEF (SEQ ID NO: 263), SYEH (SEQ ID NO: 264), SYEW (SEQ ID NO:265), SYKW (SEQ ID NO: 266), SYTY (SEQ ID NO: 267), TYDF (SEQ ID NO:268), TYEF (SEQ ID NO: 269), TYEW (SEQ ID NO: 270), TYQW (SEQ ID NO:271), TYTY (SEQ ID NO: 272), or VYEW (SEQ ID NO: 273).

Embodiment 101. The humanized antibody or binding fragment thereof ofEmbodiment 99, wherein the (X^(a)X^(b))_(z) motif is YXYXYX.

Embodiment 102. The library of Embodiment 71, wherein the ultralong CDR3comprises a X¹X²X³X⁴X⁵X_(n) motif, wherein X¹ is threonine (T), glycine(G), alanine (A), serine (S), or valine (V), wherein X² is serine (S),threonine (T), proline (P), isoleucine (I), alanine (A), valine (V), orasparagine (N), wherein X³ is valine (V), alanine (A), threonine (T), oraspartic acid (D), wherein X⁴ is histidine (H), threonine (T), arginine(R), tyrosine (Y), phenylalanine (F), or leucine (L), and wherein X⁵ isglutamine (Q), and wherein n is 27-54.

Embodiment 103. The library of Embodiment 71, wherein the ultralong CDR3comprises X_(n)(X^(a)X^(b))_(z) motif, wherein X^(a) is any amino acidresidue, X^(b) is an aromatic amino acid selected from the groupconsisting of: tyrosine (Y), phenylalanine (F), tryptophan (W), andhistidine (H), wherein n is 27-54, and wherein z is 1-4.

Embodiment 104. The library of Embodiment 71, wherein the ultralong CDR3comprises a X¹X²X³X⁴X⁵X_(n)(X^(a)X^(b))_(z) motif, wherein X₁ isthreonine (T), glycine (G), alanine (A), serine (S), or valine (V),wherein X₂ is serine (S), threonine (T), proline (P), isoleucine (I),alanine (A), valine (V), or asparagine (N), wherein X₃ is valine (V),alanine (A), threonine (T), or aspartic acid (D), wherein X₄ ishistidine (H), threonine (T), arginine (R), tyrosine (Y), phenylalanine(F), or leucine (L), wherein X₅ is glutamine (Q), X^(a) is any aminoacid residue, X^(b) is an aromatic amino acid selected from the groupconsisting of: tyrosine (Y), phenylalanine (F), tryptophan (W), andhistidine (H), wherein n is 27-54, and wherein z is 1-4.

Embodiment 105. The library of Embodiment 104, wherein the X¹X²X³X⁴X⁵motif is TTVHQ (SEQ ID NO: 153) or TSVHQ (SEQ ID NO: 154), and whereinthe (X^(a)X^(b))_(z) motif is YXYXYX.

Embodiment 106. The library of Embodiment 71, wherein the ultralong CDR3comprises: a CX¹X²X³X⁴X⁵ motif, wherein X¹ is threonine (T), glycine(G), alanine (A), serine (S), or valine (V), wherein X² is serine (S),threonine (T), proline (P), isoleucine (I), alanine (A), valine (V), orasparagine (N), wherein X³ is valine (V), alanine (A), threonine (T), oraspartic acid (D), wherein X⁴ is histidine (H), threonine (T), arginine(R), tyrosine (Y), phenylalanine (F), or leucine (L), and wherein X⁵ isglutamine (Q); a cysteine motif selected from the group consisting of:CX₁₀CX₅CX₅CXCX₇C (SEQ ID NO: 41), CX₁₀CX₆CX₅CXCX₁₅C (SEQ ID NO: 42),CX₁₁CXCX₅C (SEQ ID NO: 43), CX₁₁CX₅CX₅CXCX₇C (SEQ ID NO: 44),CX₁₀CX₆CX₅CXCX₁₃C (SEQ ID NO: 45), CX₁₀CX₅CXCX₄CX₈C (SEQ ID NO: 46),CX₁₀CX₆CX₆CXCX₇C (SEQ ID NO: 47), CX₁₀CX₄CX₇CXCX₈C (SEQ ID NO: 48),CX₁₀CX₄CX₇CXCX₇C (SEQ ID NO: 49), CX₁₃CX₈CX₈C (SEQ ID NO: 50),CX₁₀CX₆CX₅CXCX₇C (SEQ ID NO: 51), CX₁₀CX₅CX₅C (SEQ ID NO: 52),CX₁₀CX₅CX₆CXCX₇C (SEQ ID NO: 53), CX₁₀CX₆CX₅CX₇CX₉C (SEQ ID NO: 54),CX₉CX₇CX₅CXCX₇C (SEQ ID NO: 55), CX₁₀CX₆CX₅CXCX₉C (SEQ ID NO: 56),CX₁₀CXCX₄CX₅CX₁₁C (SEQ ID NO: 57), CX₇CX₃CX₆CX₅CXCX₅CX₁₀C (SEQ ID NO:58), CX₁₀CXCX₄CX₅CXCX₂CX₃C (SEQ ID NO: 59), CX₁₆CX₅CXC (SEQ ID NO: 60),CX₆CX₄CXCX₄CX₅C (SEQ ID NO: 61), CX₁₁CX₄CX₅CX₆CX₃C (SEQ ID NO: 62),CX₈CX₂CX₆CX₅C (SEQ ID NO: 63), CX₁₀CX₅CX₅CXCX₁₀C (SEQ ID NO: 64),CX₁₀CXCX₆CX₄CXC (SEQ ID NO: 65), CX₁₀CX₅CX₅CXCX₂C (SEQ ID NO: 66),CX₁₄CX₂CX₃CXCXC (SEQ ID NO: 67), CX₁₅CX₅CXC (SEQ ID NO: 68),CX₄CX₆CX₉CX₂CX₁₁C (SEQ ID NO: 69), CX₆CX₄CX₅CX₅CX₁₂C (SEQ ID NO: 70),CX₇CX₃CXCXCX₄CX₅CX₉C (SEQ ID NO: 71), CX₁₀CX₆CX₅C (SEQ ID NO: 72),CX₇CX₃CX₅CX₅CX₉C (SEQ ID NO: 73), CX₇CX₅CXCX₂C (SEQ ID NO: 74),CX₁₀CXCX₆C (SEQ ID NO: 75), CX₁₀CX₃CX₃CX₅CX₇CXCX₆C (SEQ ID NO: 76),CX₁₀CX₄CX₅CX₁₂CX₂C (SEQ ID NO: 77), CX₁₂CX₄CX₅CXCXCX₉CX₃C (SEQ ID NO:78), CX₁₂CX₄CX₅CX₁₂CX₂C (SEQ ID NO: 79), CX₁₀CX₆CX₅CXCX₁₁C (SEQ ID NO:80), CX₁₆CX₅CXCXCX₁₄C (SEQ ID NO: 81), CX₁₀CX₅CXCX₈CX₆C (SEQ ID NO: 82),CX₁₂CX₄CX₅CX₈CX₂C (SEQ ID NO: 83), CX₁₂CX₅CX₅CXCX₈C (SEQ ID NO: 84),CX₁₀CX₆CX₅CXCX₄CXCX₉C (SEQ ID NO: 85), CX₁₁CX₄CX₅CX₈CX₂C (SEQ ID NO:86), CX₁₀CX₆CX₅CX₈CX₂C (SEQ ID NO: 87), CX₁₀CX₆CX₅CXCX₈C (SEQ ID NO:88), CX₁₀CX₆CX₅CXCX₃CX₈CX₂C (SEQ ID NO: 89), CX₁₀CX₆CX₅CX₃CX₈C (SEQ IDNO: 90), CX₁₀CX₆CX₅CXCX₂CX₆CX₅C (SEQ ID NO: 91), CX₇CX₆CX₃CX₃CX₉C (SEQID NO: 92), CX₉CX₈CX₅CX₆CX₅C (SEQ ID NO: 93), CX₁₀CX₂CX₂CX₇CXCX₁₁CX₅C(SEQ ID NO: 94), and CX₁₀CX₆CX₅CXCX₂CX₈CX₄C (SEQ ID NO: 95); and a(X^(a)X^(b))_(z) motif, X^(a) is any amino acid residue, X^(b) is anaromatic amino acid selected from the group consisting of: tyrosine (Y),phenylalanine (F), tryptophan (W), and histidine (H), and wherein z is1-4.

Embodiment 107. The library of Embodiment 71, wherein the ultralong CDR3comprises: a CX¹X²X³X⁴X⁵ motif, wherein X¹ is threonine (T), glycine(G), alanine (A), serine (S), or valine (V), wherein X² is serine (S),threonine (T), proline (P), isoleucine (I), alanine (A), valine (V), orasparagine (N), wherein X³ is valine (V), alanine (A), threonine (T), oraspartic acid (D), wherein X⁴ is histidine (H), threonine (T), arginine(R), tyrosine (Y), phenylalanine (F), or leucine (L), and wherein X⁵ isglutamine (Q); a cysteine motif selected from the group consisting of:wherein the cysteine motif is selected from the group consisting of:CCX₃CXCX₃CX₂CCXCX₅CX₉CX₅CXC (SEQ ID NO: 96), CX₆CX₂CX₅CX₄CCXCX₄CX₆CXC(SEQ ID NO: 97), CX₇CXCX₅CX₄CCCX₄CX₆CXC (SEQ ID NO: 98),CX₉CX₃CXCX₂CXCCCX₆CX₄C (SEQ ID NO: 99), CX₅CX₃CXCX₄CX₄CCX₁₀CX₂CC (SEQ IDNO: 100), CX₅CXCX₁CXCX₃CCX₃CX₄CX₁₀C (SEQ ID NO: 101),CX₉CCCX₃CX₄CCCX₅CX₆C (SEQ ID NO: 102), CCX₈CX₅CX₄CX₃CX₄CCXCX₁C (SEQ IDNO: 103), CCX₆CCX₅CCCX₄CX₄CX₁₂C (SEQ ID NO: 104),CX₆CX₂CX₃CCCX₄CX₅CX₃CX₃C (SEQ ID NO: 105), CX₃CX₅CX₆CX₄CCXCX₅CX₄CXC (SEQID NO: 106), CX₄CX₄CCX₄CX₄CXCX₁₁CX₂CXC (SEQ ID NO: 107),CX₅CX₂CCX₅CX₄CCX₃CCX₇C (SEQ ID NO: 108), CX₅CX₅CX₃CX₂CXCCX₄CX₇CXC (SEQID NO: 109), CX₃CX₇CX₃CX₄CCXCX₂CX₅CX₂C (SEQ ID NO: 110),CX₉CX₃CXCX₄CCX₅CCCX₆C (SEQ ID NO: 111), CX₉CX₃CXCX₂CXCCX₆CX₃CX₃C (SEQ IDNO: 112), CX₈CCXCX₃CCX₃CXCX₃CX₄C (SEQ ID NO: 113),CX₉CCX₄CX₂CXCCXCX₄CX₃C (SEQ ID NO: 114), CX₁₀CXCX₃CX₂CXCCX₄CX₅CXC (SEQID NO: 115), CX₉CXCX₃CX₂CXCCX₄CX₅CXC (SEQ ID NO: 116),CX₆CCXCX₅CX₄CCXCX₅CX₂C (SEQ ID NO: 117), CX₆CCXCX₃CXCCX₃CX₄CC (SEQ IDNO: 118), CX₆CCXCX₃CXCX₂CXCX₄CX₈C (SEQ ID NO: 119),CX₄CX₂CCX₃CXCX₄CCX₂CX₃C (SEQ ID NO: 120), CX₃CX₅CX₃CCCX₄CX₉C (SEQ ID NO:121), CCX₉CX₃CXCCX₃CX₅C (SEQ ID NO: 122), CX₉CX₂CX₃CX₄CCX₄CX₅C (SEQ IDNO: 123), CX₉CX₇CX₄CCXCX₇CX₃C (SEQ ID NO: 124), CX₉CX₃CCCX₁₀CX₂CX₃C (SEQID NO: 125), CX₃CX₅CX₅CX₄CCX₁₀CX₆C (SEQ ID NO: 126), CX₉CX₅CX₄CCXCX₅CX₄C(SEQ ID NO: 127), CX₇CXCX₆CX₄CCCX₁₀C (SEQ ID NO: 128),CX₈CX₂CX₄CCX₄CX₃CX₃C (SEQ ID NO: 129), CX₇CX₅CXCX₄CCX₇CX₄C (SEQ ID NO:130), CX₁₁CX₃CX₄CCCX₈CX₂C (SEQ ID NO: 131), CX₂CX₃CX₄CCX₄CX₅CX₁₅C (SEQID NO: 132), CX₉CX₅CX₄CCX₇C (SEQ ID NO: 133), CX₉CX₇CX₃CX₂CX₆C (SEQ IDNO: 134), CX₉CX₅CX₄CCX₁₄C (SEQ ID NO: 135), CX₉CX₅CX₄CCX₈C (SEQ ID NO:136), CX₉CX₆CX₄CCXC (SEQ ID NO: 137), CX₅CCX₇CX₄CX₁₂ (SEQ ID NO: 138),CX₁₀CX₃CX₄CCX₄C (SEQ ID NO: 139), CX₉CX₄CCX₅CX₄C (SEQ ID NO: 140),CX₁₀CX₃CX₄CX₇CXC (SEQ ID NO: 141), CX₇CX₇CX₂CX₂CX₃C (SEQ ID NO: 142),CX₉CX₄CX₄CCX₆C (SEQ ID NO: 143), CX₇CXCX₃CXCX₆C (SEQ ID NO: 144),CX₇CXCX₄CXCX₄C (SEQ ID NO: 145), CX₉CX₅CX₄C (SEQ ID NO: 146), CX₃CX₆CX₈C(SEQ ID NO: 147), CX₁₀CXCX₄C (SEQ ID NO: 148), CX₁₀CCX₄C (SEQ ID NO:149), CX₁₅C (SEQ ID NO: 150), CX₁₀C (SEQ ID NO: 151), and CX₉C (SEQ IDNO: 152); and a (X^(a)X^(b))_(z) motif, wherein X^(a) is any amino acidresidue, X^(b) is an aromatic amino acid selected from the groupconsisting of: tyrosine (Y), phenylalanine (F), tryptophan (W), andhistidine (H), and wherein z is 1-4.

Embodiment 108. The library of Embodiment 90, wherein the ultralong CDR3comprises an additional sequence that is a linker.

Embodiment 109. The library of Embodiment 108, wherein the linker islinked to a C-terminus, a N-terminus, or both C-terminus and N-terminusof the non-antibody sequence.

Embodiment 110. The library of Embodiment 71, wherein the ultralong CDR3is a ruminant CDR3.

Embodiment 111. The library of Embodiment 110, wherein the ruminant is acow.

Embodiment 112. The library of Embodiment 71, wherein the humanizedantibody or binding fragment thereof comprises a human heavy chaingermline sequence that is a VH4 family member germline sequence.

Embodiment 113. The library of Embodiment 71, wherein the humanizedantibody or binding fragment thereof comprises a VH4-34 germlinesequence.

Embodiment 114. The library of Embodiment 71, wherein the humanizedantibody or binding fragment thereof comprises a human heavy chaingermline sequence that is derived from VH4-34.

Embodiment 115. The library of Embodiment 114, wherein the VH4-34germline sequence comprises a CDR1 comprising a Gly31Asp and Tyr32Lyssubstitution based on Kabat numbering.

Embodiment 116. The library of Embodiment 114, wherein the VH4-34germline sequence comprises a CDR2 comprising a Glu50Ser substitutionbased on Kabat numbering.

Embodiment 117. The library of Embodiment 114, wherein the VH4-34germline sequence comprises a CDR1 comprising Ala23Thr, Val24Ala,Tyr25Ser, Gly27Phe, Phe29Leu, Gly31Asp, Tyr32Lys, Tyr33Ala, Trp34Val,and Ser35Gly substitutions, and a CDR2 comprising Ile48Leu, Glu50Ser,Asn52Asp, His53Thr, Ser54Gly, Ser56Asn, and Asn58Gly substitutions,based on Kabat numbering.

Embodiment 118. The library of Embodiment 71, wherein the humanizedantibody or binding fragment thereof comprises the amino acid sequenceset forth in SEQ ID NO: 470.

Embodiment 119. The library of Embodiment 71, wherein the humanizedantibody or binding fragment thereof comprises the amino acid sequenceset forth in SEQ ID NO: 461, 462, 463, 464, 465, 466, 467, 468, or 469;and the amino acid sequence set forth in SEQ ID NO: 470.

Embodiment 120. The library of Embodiment 71, wherein the humanizedantibody or binding fragment thereof comprises the amino acid sequenceset forth in SEQ ID NO: 461, 462, 463, 464, 465, 466, 467, 468, or 469;the amino acid sequence set forth in SEQ ID NO: 470; and a peptidesequence, wherein the peptide sequence is positioned between SEQ ID NO:461, 462, 463, 464, 465, 466, 467, 468, or 469, and SEQ ID NO: 470.

Embodiment 121. The library of Embodiment 120, wherein the peptidesequence is a bovine sequence, a non-bovine sequence, an antibodysequence, or a non-antibody sequence.

Embodiment 122. The library of Embodiment 71, wherein the humanizedantibody or binding fragment thereof comprises a light chain variableregion sequence that is a lambda light chain variable region sequence.

Embodiment 123. The library of Embodiment 122, wherein the lambda lightchain variable region sequence is a bovine lambda light chain variableregion sequence.

Embodiment 124. The library of Embodiment 122, wherein the lambda lightchain variable region sequence is a human lambda light chain variableregion sequence.

Embodiment 125. The library of Embodiment 124, wherein the human lambdalight chain variable region sequence is VL1-51.

Embodiment 126. The library of Embodiment 124, wherein the human lambdalight chain variable region sequence is derived from VL1-51.

Embodiment 127. The library of Embodiment 126, wherein the VL1-51germline sequence comprises a CDR1 comprising Ile29Val and Asn32Glysubstitution based on Kabat numbering.

Embodiment 128. The library of Embodiment 126, wherein the VL1-51germline sequence comprises a CDR2 comprising a substitution of DNN toGDT.

Embodiment 129. The library of Embodiment 126, wherein the VL1-51germline sequence comprises a CDR2 comprising a substitution of DNNKRP(SEQ ID NO: 471) to GDTSRA (SEQ ID NO: 472).

Embodiment 130. The library of Embodiment 126, wherein the VL1-51germline sequence comprises a S2A, T5N, P8S, A12G, A13S, and P14Lsubstitution based on Kabat numbering.

Embodiment 131. The library of Embodiment 126, wherein the VL1-51germline sequence comprises a S2A, T5N, P8S, A12G, A13S, and P14Lsubstitution based on Kabat numbering, and a CDR2 comprising asubstitution of DNN to GDT.

Embodiment 132. The library of Embodiment 71, wherein the humanizedantibody or binding fragment thereof comprising the amino acid sequenceset forth in SEQ ID NO: 440, 441, 442, 443, or 444.

Embodiment 133. The library of any one of Embodiments 71-132, whereinthe humanized antibodies or binding fragments thereof are present in aspatially addressed format.

Embodiment 134. A method of humanizing an antibody variable regioncomprising the step of genetically combining a nucleic acid sequenceencoding a non-human ultralong CDR3 with a nucleic acid sequenceencoding a human variable region framework (FR) sequence.

Embodiment 135. A method of generating a library of humanized antibodiesthat comprises an ultralong CDR3, the method comprising: combining anucleic acid sequence encoding an ultralong CDR3 with a nucleic acidsequence encoding a human variable region framework (FR) sequence toproduce nucleic acids encoding for humanized antibodies that comprisesan ultralong CDR3; and expressing the nucleic acids encoding forhumanized antibodies that comprises an ultralong CDR3 to generate alibrary of humanized antibodies that comprises an ultralong CDR3.

Embodiment 136. A method of generating a library of humanized antibodiesor binding fragments thereof comprising an ultralong CDR3 that comprisesa non-antibody sequence, the method comprising: combining a nucleic acidsequence encoding an ultralong CDR3, a nucleic acid sequence encoding ahuman variable region framework (FR) sequence, and a nucleic acidsequence encoding a non-antibody sequence to produce nucleic acidsencoding humanized antibodies or binding fragments thereof comprising anultralong CDR3 and a non-antibody sequence, and expressing the nucleicacids encoding humanized antibodies or binding fragments thereofcomprising an ultralong CDR3 and a non-antibody sequence to generate alibrary of humanized antibodies or binding fragments thereof comprisingan ultralong CDR3 and a non-antibody sequence.

Embodiment 137. A library of humanized antibodies or binding fragmentsthereof comprising an ultralong CDR3 that comprises a non-antibodysequence.

Embodiment 138. A method of generating a library of humanized antibodiesor binding fragments thereof comprising an ultralong CDR3 that comprisesa cysteine motif, the method comprising: combining a human variableregion framework (FR) sequence, and a nucleic acid sequence encoding anultralong CDR3 and a cysteine motif; introducing one or more nucleotidechanges to the nucleic acid sequence encoding one or more amino acidresidues that are positioned between one or more cysteine residues inthe cysteine motif for nucleotides encoding different amino acidresidues to produce nucleic acids encoding humanized antibodies orbinding fragments thereof comprising an ultralong CDR3 and a cysteinemotif with one or more nucleotide changes introduced between one or morecysteine residues in the cysteine domain; and expressing the nucleicacids encoding humanized antibodies or binding fragments thereofcomprising an ultralong CDR3 and a cysteine motif with one or morenucleotide changes introduced between one or more cysteine residues inthe cysteine domain to generate a library of humanized antibodies orbinding fragments thereof comprising an ultralong CDR3 and a cysteinemotif with one or more amino acid changes introduced between one or morecysteine residues in the cysteine domain.

Embodiment 139. A library of humanized antibodies or binding fragmentsthereof comprising an ultralong CDR3 that comprises a cysteine motif,wherein the antibodies or binding fragments comprise one or moresubstitutions of amino acid residues that are positioned betweencysteine residues in the cysteine motif.

Embodiment 140. A method of generating a library of humanized antibodiesor binding fragments thereof comprising a bovine ultralong CDR3, themethod comprising: combining a nucleic acid sequence encoding a humanvariable region framework (FR) sequence and a nucleic acid encoding abovine ultralong CDR3, and expressing the nucleic acids encoding a humanvariable region framework (FR) sequence and a nucleic acid encoding abovine ultralong CDR3 to generate a library of humanized antibodies orbinding fragments thereof comprising a bovine ultralong CDR3.

Embodiment 141. A library of humanized antibodies or binding fragmentsthereof comprising a bovine ultralong CDR3.

Embodiment 142. A CDR3 scaffold comprising a X¹X²X³X⁴X⁵ motif, whereinX¹ is threonine (T), glycine (G), alanine (A), serine (S), or valine(V), wherein X² is serine (S), threonine (T), proline (P), isoleucine(I), alanine (A), valine (V), or asparagine (N), wherein X³ is valine(V), alanine (A), threonine (T), or aspartic acid (D), wherein X⁴ ishistidine (H), threonine (T), arginine (R), tyrosine (Y), phenylalanine(F), or leucine (L), and wherein X⁵ is glutamine (Q).

Embodiment 143. The CDR3 scaffold of Embodiment 142, wherein the CDR3scaffold is 35 amino acids in length or longer, 40 amino acids in lengthor longer, 45 amino acids in length or longer, 50 amino acids in lengthor longer, 55 amino acids in length or longer, or 60 amino acids inlength or longer.

Embodiment 144. The CDR3 scaffold of Embodiment 143, wherein the CDR3scaffold is 35 amino acids in length or longer.

Embodiment 145. The CDR3 scaffold of Embodiment 143, wherein the CDR3scaffold comprises 3 or more cysteine residues, 4 or more cysteineresidues, 5 or more cysteine residues, 6 or more cysteine residues, 7 ormore cysteine residues, 8 or more cysteine residues, 9 or more cysteineresidues, 10 or more cysteine residues, 11 or more cysteine residues, or12 or more cysteine residues.

Embodiment 146. The CDR3 scaffold of Embodiment 145, wherein the CDR3scaffold comprises 3 or more cysteine residues.

Embodiment 147. The CDR3 scaffold of Embodiment 142, wherein the CDR3scaffold comprises a cysteine motif.

Embodiment 148. The CDR3 scaffold of Embodiment 147, wherein thecysteine motif is selected from the group consisting of:

(SEQ ID NO: 41) CX₁₀CX₅CX₅CXCX₇C,  (SEQ ID NO: 42) CX₁₀CX₆CX₅CXCX₁₅C, (SEQ ID NO: 43) CX₁₁CXCX₅C, (SEQ ID NO: 44) CX₁₁CX₅CX₅CXCX₇C,(SEQ ID NO: 45) CX₁₀CX₆CX₅CXCX₁₃C, (SEQ ID NO: 46) CX₁₀CX₅CXCX₄CX₈C, (SEQ ID NO: 47) CX₁₀CX₆CX₆CXCX₇C, (SEQ ID NO: 48) CX₁₀CX₄CX₇CXCX₈C, (SEQ ID NO: 49) CX₁₀CX₄CX₇CXCX₇C, (SEQ ID NO: 50) CX₁₃CX₈CX₈C, (SEQ ID NO: 51) CX₁₀CX₆CX₅CXCX₇C,  (SEQ ID NO: 52) CX₁₀CX₅CX₅C, (SEQ ID NO: 53) CX₁₀CX₅CX₆CXCX₇C,  (SEQ ID NO: 54) CX₁₀CX₆CX₅CX₇CX₉C, (SEQ ID NO: 55) CX₉CX₇CX₅CXCX₇C,  (SEQ ID NO: 56) CX₁₀CX₆CX₅CXCX₉C,(SEQ ID NO: 57) CX₁₀CXCX₄CX₅CX₁₁C,  (SEQ ID NO: 58)CX₇CX₃CX₆CX₅CXCX₅CX₁₀C, (SEQ ID NO: 59) CX₁₀CXCX₄CX₅CXCX₂CX₃C, (SEQ ID NO: 60) CX₁₆CX₅CXC, (SEQ ID NO: 61) CX₆CX₄CXCX₄CX₅C, (SEQ ID NO: 62) CX₁₁CX₄CX₅CX₆CX₃C, (SEQ ID NO: 63) CX₈CX₂CX₆CX₅C,(SEQ ID NO: 64) CX₁₀CX₅CX₅CXCX₁₀C, (SEQ ID NO: 65) CX₁₀CXCX₆CX₄CXC, (SEQ ID NO: 66) CX₁₀CX₅CX₅CXCX₂C, (SEQ ID NO: 67) CX₁₄CX₂CX₃CXCXC,(SEQ ID NO: 68) CX₁₅CX₅CXC, (SEQ ID NO: 69) CX₄CX₆CX₉CX₂CX₁₁C,(SEQ ID NO: 70) CX₆CX₄CX₅CX₅CX₁₂C, (SEQ ID NO: 71)CX₇CX₃CXCXCX₄CX₅CX₉C,  (SEQ ID NO: 72) CX₁₀CX₆CX₅C, (SEQ ID NO: 73)CX₇CX₃CX₅CX₅CX₉C,  (SEQ ID NO: 74) CX₇CX₅CXCX₂C,  (SEQ ID NO: 75)CX₁₀CXCX₆C,  (SEQ ID NO: 76) CX₁₀CX₃CX₃CX₅CX₇CXCX₆C,  (SEQ ID NO: 77)CX₁₀CX₄CX₅CX₁₂CX₂C,  (SEQ ID NO: 78) CX₁₂CX₄CX₅CXCXCX₉CX₃C, (SEQ ID NO: 79) CX₁₂CX₄CX₅CX₁₂CX₂C,  (SEQ ID NO: 80) CX₁₀CX₆CX₅CXCX₁₁C, (SEQ ID NO: 81) CX₁₆CX₅CXCXCX₁₄C,  (SEQ ID NO: 82) CX₁₀CX₅CXCX₈CX₆C, (SEQ ID NO: 83) CX₁₂CX₄CX₅CX₈CX₂C, (SEQ ID NO: 84) CX₁₂CX₅CX₅CXCX₈C, (SEQ ID NO: 85) CX₁₀CX₆CX₅CXCX₄CXCX₉C, (SEQ ID NO: 86)CX₁₁CX₄CX₅CX₈CX₂C, (SEQ ID NO: 87) CX₁₀CX₆CX₅CX₈CX₂C, (SEQ ID NO: 88)CX₁₀CX₆CX₅CXCX₈C,  (SEQ ID NO: 89) CX₁₀CX₆CX₅CXCX₃CX₈CX₂C,(SEQ ID NO: 90) CX₁₀CX₆CX₅CX₃CX₈C,  (SEQ ID NO: 91)CX₁₀CX₆CX₅CXCX₂CX₆CX₅C, (SEQ ID NO: 92) CX₇CX₆CX₃CX₃CX₉C, (SEQ ID NO: 93) CX₉CX₈CX₅CX₆CX₅C, (SEQ ID NO: 94)CX₁₀CX₂CX₂CX₇CXCX₁₁CX₅C,  and  (SEQ ID NO: 95) CX₁₀CX₆CX₅CXCX₂CX₈CX₄C.

Embodiment 149. The CDR3 scaffold of Embodiment 147, wherein thecysteine motif is selected from the group consisting of:

(SEQ ID NO: 96) CCX₃CXCX₃CX₂CCXCX₅CX₉CX₅CXC,  (SEQ ID NO: 97)CX₆CX₂CX₅CX₄CCXCX₄CX₆CXC,  (SEQ ID NO: 98) CX₇CXCX₅CX₄CCCX₄CX₆CXC,(SEQ ID NO: 99) CX₉CX₃CXCX₂CXCCCX₆CX₄C,  (SEQ ID NO: 100)CX₅CX₃CXCX₄CX₄CCX₁₀CX₂CC,  (SEQ ID NO: 101) CX₅CXCX₁CXCX₃CCX₃CX₄CX₁₀C,(SEQ ID NO: 102) CX₉CCCX₃CX₄CCCX₅CX₆C,  (SEQ ID NO: 103)CCX₈CX₅CX₄CX₃CX₄CCXCX₁C, (SEQ ID NO: 104) CCX₆CCX₅CCCX₄CX₄CX₁₂C,(SEQ ID NO: 105) CX₆CX₂CX₃CCCX₄CX₅CX₃CX₃C,  (SEQ ID NO: 106)CX₃CX₅CX₆CX₄CCXCX₅CX₄CXC, (SEQ ID NO: 107) CX₄CX₄CCX₄CX₄CXCX₁₁CX₂CXC,(SEQ ID NO: 108) CX₅CX₂CCX₅CX₄CCX₃CCX₇C,  (SEQ ID NO: 109)CX₅CX₅CX₃CX₂CXCCX₄CX₇CXC, (SEQ ID NO: 110) CX₃CX₇CX₃CX₄CCXCX₂CX₅CX₂C,(SEQ ID NO: 111) CX₉CX₃CXCX₄CCX₅CCCX₆C,  (SEQ ID NO: 112)CX₉CX₃CXCX₂CXCCX₆CX₃CX₃C, (SEQ ID NO: 113) CX₈CCXCX₃CCX₃CXCX₃CX₄C,(SEQ ID NO: 114) CX₉CCX₄CX₂CXCCXCX₄CX₃C,  (SEQ ID NO: 115)CX₁₀CXCX₃CX₂CXCCX₄CX₅CXC, (SEQ ID NO: 116) CX₉CXCX₃CX₂CXCCX₄CX₅CXC,(SEQ ID NO: 117) CX₆CCXCX₅CX₄CCXCX₅CX₂C,  (SEQ ID NO: 118)CX₆CCXCX₃CXCCX₃CX₄CC, (SEQ ID NO: 119) CX₆CCXCX₃CXCX₂CXCX₄CX₈C,(SEQ ID NO: 120) CX₄CX₂CCX₃CXCX₄CCX₂CX₃C,  (SEQ ID NO: 121)CX₃CX₅CX₃CCCX₄CX₉C,  (SEQ ID NO: 122) CCX₉CX₃CXCCX₃CX₅C, (SEQ ID NO: 123) CX₉CX₂CX₃CX₄CCX₄CX₅C,  (SEQ ID NO: 124)CX₉CX₇CX₄CCXCX₇CX₃C,  (SEQ ID NO: 125) CX₉CX₃CCCX₁₀CX₂CX₃C, (SEQ ID NO: 126) CX₃CX₅CX₅CX₄CCX₁₀CX₆C,  (SEQ ID NO: 127)CX₉CX₅CX₄CCXCX₅CX₄C,  (SEQ ID NO: 128) CX₇CXCX₆CX₄CCCX₁₀C, (SEQ ID NO: 129) CX₈CX₂CX₄CCX₄CX₃CX₃C,  (SEQ ID NO: 130)CX₇CX₅CXCX₄CCX₇CX₄C,  (SEQ ID NO: 131) CX₁₁CX₃CX₄CCCX₈CX₂C, (SEQ ID NO: 132) CX₂CX₃CX₄CCX₄CX₅CX₁₅C,  (SEQ ID NO: 133)CX₉CX₅CX₄CCX₇C,  (SEQ ID NO: 134) CX₉CX₇CX₃CX₂CX₆C,  (SEQ ID NO: 135)CX₉CX₅CX₄CCX₁₄C, (SEQ ID NO: 136) CX₉CX₅CX₄CCX₈C,  (SEQ ID NO: 137)CX₉CX₆CX₄CCXC, (SEQ ID NO: 138) CX₅CCX₇CX₄CX₁₂,  (SEQ ID NO: 139)CX₁₀CX₃CX₄CCX₄C, (SEQ ID NO: 140) CX₉CX₄CCX₅CX₄C,  (SEQ ID NO: 141)CX₁₀CX₃CX₄CX₇CXC, (SEQ ID NO: 142) CX₇CX₇CX₂CX₂CX₃C,  (SEQ ID NO: 143)CX₉CX₄CX₄CCX₆C, (SEQ ID NO: 144) CX₇CXCX₃CXCX₆C,  (SEQ ID NO: 145)CX₇CXCX₄CXCX₄C, (SEQ ID NO: 146) CX₉CX₅CX₄C,  (SEQ ID NO: 147)CX₃CX₆CX₈C,  (SEQ ID NO: 148) CX₁₀CXCX₄C,  (SEQ ID NO: 149) CX₁₀CCX₄C, (SEQ ID NO: 150) CX₁₅C,  (SEQ ID NO: 151) CX₁₀C, and  (SEQ ID NO: 152)CX₉C.

Embodiment 150. The CDR3 scaffold of Embodiment 142, wherein the CDR3scaffold comprises 2 to 6 disulfide bonds.

Embodiment 151. The CDR3 scaffold of Embodiment 142, wherein theX¹X²X³X⁴X⁵ motif in the CDR3 scaffold is TTVHQ (SEQ ID NO: 153), TSVHQ(SEQ ID NO: 154), SSVTQ (SEQ ID NO: 155), STVHQ (SEQ ID NO: 156), ATVRQ(SEQ ID NO: 157), TTVYQ (SEQ ID NO: 158), SPVHQ (SEQ ID NO: 159), ATVYQ(SEQ ID NO: 160), TAVYQ (SEQ ID NO: 161), TNVHQ (SEQ ID NO: 162), ATVHQ(SEQ ID NO: 163), STVYQ (SEQ ID NO: 164), TIVHQ (SEQ ID NO: 165), AIVYQ(SEQ ID NO: 166), TTVFQ (SEQ ID NO: 167), AAVFQ (SEQ ID NO: 168), GTVHQ(SEQ ID NO: 169), ASVHQ (SEQ ID NO: 170), TAVFQ (SEQ ID NO: 171), ATVFQ(SEQ ID NO: 172), AAAHQ (SEQ ID NO: 173), VVVYQ (SEQ ID NO: 174), GTVFQ(SEQ ID NO: 175), TAVHQ (SEQ ID NO: 176), ITVHQ (SEQ ID NO: 177), ITAHQ(SEQ ID NO: 178), VTVHQ (SEQ ID NO: 179); AAVHQ (SEQ ID NO: 180), GTVYQ(SEQ ID NO: 181), TTVLQ (SEQ ID NO: 182), TTTHQ (SEQ ID NO: 183), orTTDYQ (SEQ ID NO: 184).

Embodiment 152. The CDR3 scaffold of Embodiment 142, wherein the CDR3scaffold comprises a CX¹X²X³X⁴X⁵ motif.

Embodiment 153. The CDR3 scaffold of Embodiment 152, wherein theCX¹X²X³X⁴X⁵ motif in the CDR3 scaffold is CTTVHQ (SEQ ID NO: 185),CTSVHQ (SEQ ID NO: 186), CSSVTQ (SEQ ID NO: 187), CSTVHQ (SEQ ID NO:188), CATVRQ (SEQ ID NO: 189), CTTVYQ (SEQ ID NO: 190), CSPVHQ (SEQ IDNO: 191), CATVYQ (SEQ ID NO: 192), CTAVYQ (SEQ ID NO: 193), CTNVHQ (SEQID NO: 194), CATVHQ (SEQ ID NO: 195), CSTVYQ (SEQ ID NO: 196), CTIVHQ(SEQ ID NO: 197), CAIVYQ (SEQ ID NO: 198), CTTVFQ (SEQ ID NO: 199),CAAVFQ (SEQ ID NO: 200), CGTVHQ (SEQ ID NO: 201), CASVHQ (SEQ ID NO:202), CTAVFQ (SEQ ID NO: 203), CATVFQ (SEQ ID NO: 204), CAAAHQ (SEQ IDNO: 205), CVVVYQ (SEQ ID NO: 206), CGTVFQ (SEQ ID NO: 207), CTAVHQ (SEQID NO: 208), CITVHQ (SEQ ID NO: 209), CITAHQ (SEQ ID NO: 210), CVTVHQ(SEQ ID NO: 211); CAAVHQ (SEQ ID NO: 212), CGTVYQ (SEQ ID NO: 213),CTTVLQ (SEQ ID NO: 214), CTTTHQ (SEQ ID NO: 215), or CTTDYQ (SEQ ID NO:216).

Embodiment 154. The CDR3 scaffold of Embodiment 142, wherein the CDR3scaffold comprises a (X^(a)X^(b))_(z) motif, wherein X^(a) is any aminoacid residue, X^(b) is an aromatic amino acid selected from the groupconsisting of: tyrosine (Y), phenylalanine (F), tryptophan (W), andhistidine (H), and wherein z is 1-4.

Embodiment 155. The CDR3 scaffold of Embodiment 154, wherein the(X^(a)X^(b))_(z) motif in the CDR3 scaffold is CYTYNYEF (SEQ ID NO:217), HYTYTYDF (SEQ ID NO: 218), HYTYTYEW (SEQ ID NO: 219), KHRYTYEW(SEQ ID NO: 220), NYIYKYSF (SEQ ID NO: 221), PYIYTYQF (SEQ ID NO: 222),SFTYTYEW (SEQ ID NO: 223), SYIYIYQW (SEQ ID NO: 224), SYNYTYSW (SEQ IDNO: 225), SYSYSYEY (SEQ ID NO: 226), SYTYNYDF (SEQ ID NO: 227), SYTYNYEW(SEQ ID NO: 228), SYTYNYQF (SEQ ID NO: 229), SYVWTHNF (SEQ ID NO: 230),TYKYVYEW (SEQ ID NO: 231), TYTYTYEF (SEQ ID NO: 232), TYTYTYEW (SEQ IDNO: 233), VFTYTYEF (SEQ ID NO: 234), AYTYEW (SEQ ID NO: 235), DYIYTY(SEQ ID NO: 236), IHSYEF (SEQ ID NO: 237), SFTYEF (SEQ ID NO: 238),SHSYEF (SEQ ID NO: 239), THTYEF (SEQ ID NO: 240), TWTYEF (SEQ ID NO:241), TYNYEW (SEQ ID NO: 242), TYSYEF (SEQ ID NO: 243), TYSYEH (SEQ IDNO: 244), TYTYDF (SEQ ID NO: 245), TYTYEF (SEQ ID NO: 246), TYTYEW (SEQID NO: 247), AYEF (SEQ ID NO: 248), AYSF (SEQ ID NO: 249), AYSY (SEQ IDNO: 250), CYSF (SEQ ID NO: 251), DYTY (SEQ ID NO: 252), KYEH (SEQ ID NO:253), KYEW (SEQ ID NO: 254), MYEF (SEQ ID NO: 255), NWIY (SEQ ID NO:256), NYDY (SEQ ID NO: 257), NYQW (SEQ ID NO: 258), NYSF (SEQ ID NO:259), PYEW (SEQ ID NO: 260), RYNW (SEQ ID NO: 261), RYTY (SEQ ID NO:262), SYEF (SEQ ID NO: 263), SYEH (SEQ ID NO: 264), SYEW (SEQ ID NO:265), SYKW (SEQ ID NO: 266), SYTY (SEQ ID NO: 267), TYDF (SEQ ID NO:268), TYEF (SEQ ID NO: 269), TYEW (SEQ ID NO: 270), TYQW (SEQ ID NO:271), TYTY (SEQ ID NO: 272), or VYEW (SEQ ID NO: 273).

Embodiment 156. The CDR3 scaffold of Embodiment 154, wherein the(X^(a)X^(b))_(z) motif in the CDR3 scaffold is YXYXYX.

Embodiment 157. The CDR3 scaffold of Embodiment 142, wherein the CDR3scaffold comprises a X¹X²X³X⁴X⁵X_(n) motif, wherein X¹ is threonine (T),glycine (G), alanine (A), serine (S), or valine (V), wherein X² isserine (S), threonine (T), proline (P), isoleucine (I), alanine (A),valine (V), or asparagine (N), wherein X³ is valine (V), alanine (A),threonine (T), or aspartic acid (D), wherein X⁴ is histidine (H),threonine (T), arginine (R), tyrosine (Y), phenylalanine (F), or leucine(L), and wherein X⁵ is glutamine (Q), and wherein n is 27-54.

Embodiment 158. The CDR3 scaffold of Embodiment 142, wherein the CDR3scaffold comprises a X_(n)(X^(a)X^(b))_(z) motif, wherein X^(a) is anyamino acid residue, X^(b) is an aromatic amino acid selected from thegroup consisting of: tyrosine (Y), phenylalanine (F), tryptophan (W),and histidine (H), wherein n is 27-54, and wherein z is 1-4.

Embodiment 159. The CDR3 scaffold of Embodiment 142, wherein the CDR3scaffold comprises a X¹X²X³X⁴X⁵X_(n)(X^(a)X^(b))_(z) motif, wherein X₁is threonine (T), glycine (G), alanine (A), serine (S), or valine (V),wherein X₂ is serine (S), threonine (T), proline (P), isoleucine (I),alanine (A), valine (V), or asparagine (N), wherein X₃ is valine (V),alanine (A), threonine (T), or aspartic acid (D), wherein X₄ ishistidine (H), threonine (T), arginine (R), tyrosine (Y), phenylalanine(F), or leucine (L), wherein X₅ is glutamine (Q), X^(a) is any aminoacid residue, X^(b) is an aromatic amino acid selected from the groupconsisting of: tyrosine (Y), phenylalanine (F), tryptophan (W), andhistidine (H), wherein n is 27-54, and wherein z is 1-4.

Embodiment 160. The CDR3 scaffold of Embodiment 159, wherein theX¹X²X³X⁴X⁵ motif in the CDR3 scaffold is TTVHQ (SEQ ID NO: 153) or TSVHQ(SEQ ID NO: 154), and wherein the (X^(a)X^(b))_(z) motif is YXYXYX.

Embodiment 161. The CDR3 scaffold of Embodiment 142, wherein the CDR3scaffold comprises: a CX¹X²X³X⁴X⁵ motif, wherein X¹ is threonine (T),glycine (G), alanine (A), serine (S), or valine (V), wherein X² isserine (S), threonine (T), proline (P), isoleucine (I), alanine (A),valine (V), or asparagine (N), wherein X³ is valine (V), alanine (A),threonine (T), or aspartic acid (D), wherein X⁴ is histidine (H),threonine (T), arginine (R), tyrosine (Y), phenylalanine (F), or leucine(L), and wherein X⁵ is glutamine (Q); a cysteine motif selected from thegroup consisting of: CX₁₀CX₅CX₅CXCX₇C (SEQ ID NO: 41), CX₁₀CX₆CX₅CXCX₁₅C(SEQ ID NO: 42), CX₁₁CXCX₅C (SEQ ID NO: 43), CX₁₁CX₅CX₅CXCX₇C (SEQ IDNO: 44), CX₁₀CX₆CX₅CXCX₁₃C (SEQ ID NO: 45), CX₁₀CX₅CXCX₄CX₈C (SEQ ID NO:46), CX₁₀CX₆CX₆CXCX₇C (SEQ ID NO: 47), CX₁₀CX₄CX₇CXCX₈C (SEQ ID NO: 48),CX₁₀CX₄CX₇CXCX₇C (SEQ ID NO: 49), CX₁₃CX₈CX₈C (SEQ ID NO: 50),CX₁₀CX₆CX₅CXCX₇C (SEQ ID NO: 51), CX₁₀CX₅CX₅C (SEQ ID NO: 52),CX₁₀CX₅CX₆CXCX₇C (SEQ ID NO: 53), CX₁₀CX₆CX₅CX₇CX₉C (SEQ ID NO: 54),CX₉CX₇CX₅CXCX₇C (SEQ ID NO: 55), CX₁₀CX₆CX₅CXCX₉C (SEQ ID NO: 56),CX₁₀CXCX₄CX₅CX₁₁C (SEQ ID NO: 57), CX₇CX₃CX₆CX₅CXCX₅CX₁₀C (SEQ ID NO:58), CX₁₀CXCX₄CX₅CXCX₂CX₃C (SEQ ID NO: 59), CX₁₆CX₅CXC (SEQ ID NO: 60),CX₆CX₄CXCX₄CX₅C (SEQ ID NO: 61), CX₁₁CX₄CX₅CX₆CX₃C (SEQ ID NO: 62),CX₈CX₂CX₆CX₅C (SEQ ID NO: 63), CX₁₀CX₅CX₅CXCX₁₀C (SEQ ID NO: 64),CX₁₀CXCX₆CX₄CXC (SEQ ID NO: 65), CX₁₀CX₅CX₅CXCX₂C (SEQ ID NO: 66),CX₁₄CX₂CX₃CXCXC (SEQ ID NO: 67), CX₁₅CX₅CXC (SEQ ID NO: 68),CX₄CX₆CX₉CX₂CX₁₁C (SEQ ID NO: 69), CX₆CX₄CX₅CX₅CX₁₂C (SEQ ID NO: 70),CX₇CX₃CXCXCX₄CX₅CX₉C (SEQ ID NO: 71), CX₁₀CX₆CX₅C (SEQ ID NO: 72),CX₇CX₃CX₅CX₅CX₉C (SEQ ID NO: 73), CX₇CX₅CXCX₂C (SEQ ID NO: 74),CX₁₀CXCX₆C (SEQ ID NO: 75), CX₁₀CX₃CX₃CX₅CX₇CXCX₆C (SEQ ID NO: 76),CX₁₀CX₄CX₅CX₁₂CX₂C (SEQ ID NO: 77), CX₁₂CX₄CX₅CXCXCX₉CX₃C (SEQ ID NO:78), CX₁₂CX₄CX₅CX₁₂CX₂C (SEQ ID NO: 79), CX₁₀CX₆CX₅CXCX₁₁C (SEQ ID NO:80), CX₁₆CX₅CXCXCX₁₄C (SEQ ID NO: 81), CX₁₀CX₅CXCX₈CX₆C (SEQ ID NO: 82),CX₁₂CX₄CX₅CX₈CX₂C (SEQ ID NO: 83), CX₁₂CX₅CX₅CXCX₈C (SEQ ID NO: 84),CX₁₀CX₆CX₅CXCX₄CXCX₉C (SEQ ID NO: 85), CX₁₁CX₄CX₅CX₈CX₂C (SEQ ID NO:86), CX₁₀CX₆CX₅CX₈CX₂C (SEQ ID NO: 87), CX₁₀CX₆CX₅CXCX₈C (SEQ ID NO:88), CX₁₀CX₆CX₅CXCX₃CX₈CX₂C (SEQ ID NO: 89), CX₁₀CX₆CX₅CX₃CX₈C (SEQ IDNO: 90), CX₁₀CX₆CX₅CXCX₂CX₆CX₅C (SEQ ID NO: 91), CX₇CX₆CX₃CX₃CX₉C (SEQID NO: 92), CX₉CX₈CX₅CX₆CX₅C (SEQ ID NO: 93), CX₁₀CX₂CX₂CX₇CXCX₁₁CX₅C(SEQ ID NO: 94), and CX₁₀CX₆CX₅CXCX₂CX₈CX₄C (SEQ ID NO: 95); and a(X^(a)X^(b))_(z) motif, wherein X^(a) is any amino acid residue, X^(b)is an aromatic amino acid selected from the group consisting of:tyrosine (Y), phenylalanine (F), tryptophan (W), and histidine (H), andwherein z is 1-4.

Embodiment 162. The CDR3 scaffold of Embodiment 142, wherein the CDR3scaffold comprises: a CX¹X²X³X⁴X⁵ motif, wherein X¹ is threonine (T),glycine (G), alanine (A), serine (S), or valine (V), wherein X² isserine (S), threonine (T), proline (P), isoleucine (I), alanine (A),valine (V), or asparagine (N), wherein X³ is valine (V), alanine (A),threonine (T), or aspartic acid (D), wherein X⁴ is histidine (H),threonine (T), arginine (R), tyrosine (Y), phenylalanine (F), or leucine(L), and wherein X⁵ is glutamine (Q); a cysteine motif selected from thegroup consisting of: wherein the cysteine motif is selected from thegroup consisting of: CCX₃CXCX₃CX₂CCXCX₅CX₉CX₅CXC (SEQ ID NO: 96),CX₆CX₂CX₅CX₄CCXCX₄CX₆CXC (SEQ ID NO: 97), CX₇CXCX₅CX₄CCCX₄CX₆CXC (SEQ IDNO: 98), CX₉CX₃CXCX₂CXCCCX₆CX₄C (SEQ ID NO: 99),CX₅CX₃CXCX₄CX₄CCX₁₀CX₂CC (SEQ ID NO: 100), CX₅CXCX₁CXCX₃CCX₃CX₄CX₁₀C(SEQ ID NO: 101), CX₉CCCX₃CX₄CCCX₅CX₆C (SEQ ID NO: 102),CCX₈CX₅CX₄CX₃CX₄CCXCX₁C (SEQ ID NO: 103), CCX₆CCX₅CCCX₄CX₄CX₁₂C (SEQ IDNO: 104), CX₆CX₂CX₃CCCX₄CX₅CX₃CX₃C (SEQ ID NO: 105),CX₃CX₅CX₆CX₄CCXCX₅CX₄CXC (SEQ ID NO: 106), CX₄CX₄CCX₄CX₄CXCX₁₁CX₂CXC(SEQ ID NO: 107), CX₅CX₂CCX₅CX₄CCX₃CCX₇C (SEQ ID NO: 108),CX₅CX₅CX₃CX₂CXCCX₄CX₇CXC (SEQ ID NO: 109), CX₃CX₇CX₃CX₄CCXCX₂CX₅CX₂C(SEQ ID NO: 110), CX₉CX₃CXCX₄CCX₅CCCX₆C (SEQ ID NO: 111),CX₉CX₃CXCX₂CXCCX₆CX₃CX₃C (SEQ ID NO: 112), CX₈CCXCX₃CCX₃CXCX₃CX₄C (SEQID NO: 113), CX₉CCX₄CX₂CXCCXCX₄CX₃C (SEQ ID NO: 114),CX₁₀CXCX₃CX₂CXCCX₄CX₅CXC (SEQ ID NO: 115), CX₉CXCX₃CX₂CXCCX₄CX₅CXC (SEQID NO: 116), CX₆CCXCX₅CX₄CCXCX₅CX₂C (SEQ ID NO: 117),CX₆CCXCX₃CXCCX₃CX₄CC (SEQ ID NO: 118), CX₆CCXCX₃CXCX₂CXCX₄CX₈C (SEQ IDNO: 119), CX₄CX₂CCX₃CXCX₄CCX₂CX₃C (SEQ ID NO: 120), CX₃CX₅CX₃CCCX₄CX₉C(SEQ ID NO: 121), CCX₉CX₃CXCCX₃CX₅C (SEQ ID NO: 122),CX₉CX₂CX₃CX₄CCX₄CX₅C (SEQ ID NO: 123), CX₉CX₇CX₄CCXCX₇CX₃C (SEQ ID NO:124), CX₉CX₃CCCX₁₀CX₂CX₃C (SEQ ID NO: 125), CX₃CX₅CX₅CX₄CCX₁₀CX₆C (SEQID NO: 126), CX₉CX₅CX₄CCXCX₅CX₄C (SEQ ID NO: 127), CX₇CXCX₆CX₄CCCX₁₀C(SEQ ID NO: 128), CX₈CX₂CX₄CCX₄CX₃CX₃C (SEQ ID NO: 129),CX₇CX₅CXCX₄CCX₇CX₄C (SEQ ID NO: 130), CX₁₁CX₃CX₄CCCX₈CX₂C (SEQ ID NO:131), CX₂CX₃CX₄CCX₄CX₅CX₁₅C (SEQ ID NO: 132), CX₉CX₅CX₄CCX₇C (SEQ ID NO:133), CX₉CX₇CX₃CX₂CX₆C (SEQ ID NO: 134), CX₉CX₅CX₄CCX₁₄C (SEQ ID NO:135), CX₉CX₅CX₄CCX₈C (SEQ ID NO: 136), CX₉CX₆CX₄CCXC (SEQ ID NO: 137),CX₅CCX₇CX₄CX₁₂ (SEQ ID NO: 138), CX₁₀CX₃CX₄CCX₄C (SEQ ID NO: 139),CX₉CX₄CCX₅CX₄C (SEQ ID NO: 140), CX₁₀CX₃CX₄CX₇CXC (SEQ ID NO: 141),CX₇CX₇CX₂CX₂CX₃C (SEQ ID NO: 142), CX₉CX₄CX₄CCX₆C (SEQ ID NO: 143),CX₇CXCX₃CXCX₆C (SEQ ID NO: 144), CX₇CXCX₄CXCX₄C (SEQ ID NO: 145),CX₉CX₅CX₄C (SEQ ID NO: 146), CX₃CX₆CX₈C (SEQ ID NO: 147), CX₁₀CXCX₄C(SEQ ID NO: 148), CX₁₀CCX₄C (SEQ ID NO: 149), CX₁₅C (SEQ ID NO: 150),CX₁₀C (SEQ ID NO: 151), and CX₉C (SEQ ID NO: 152); and a (X^(a)X^(b)),motif, wherein X^(a) is any amino acid residue, X^(b) is an aromaticamino acid selected from the group consisting of: tyrosine (Y),phenylalanine (F), tryptophan (W), and histidine (H), and wherein z is1-4.

Embodiment 163. The CDR3 scaffold of Embodiment 142, wherein the CDR3scaffold comprises SEQ ID NO: 40 or a derivative thereof.

Embodiment 164. The CDR3 scaffold of Embodiment 142, wherein the CDR3scaffold comprises amino acid residues 3-6 of any of one SEQ ID NO: 1-4.

Embodiment 165. The CDR3 scaffold of Embodiment 142, wherein the CDR3scaffold comprises a non-human DH or a derivative thereof.

Embodiment 166. The CDR3 scaffold of Embodiment 165, wherein thenon-human DH is SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8,SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, or SEQ ID NO: 12

Embodiment 167. The CDR3 scaffold of Embodiment 142, wherein the CDR3scaffold comprises a JH sequence or a derivative thereof.

Embodiment 168. The CDR3 scaffold of Embodiment 167, wherein the JHsequence is SEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO: 15, SEQ ID NO: 16,or SEQ ID NO: 17.

Embodiment 169. The CDR3 scaffold of Embodiment 142, wherein the CDR3scaffold comprises: a non-human VH sequence or a derivative thereof; anon-human DH sequence or a derivative thereof; and/or a JH sequence orderivative thereof.

Embodiment 170. The CDR3 scaffold of Embodiment 169, wherein the CDR3scaffold comprises an additional amino acid sequence comprising two tosix amino acid residues or more positioned between the VH sequence andthe DH sequence.

Embodiment 171. The CDR3 scaffold of Embodiment 170, wherein theadditional amino acid sequence is selected from the group consisting of:IR, IF, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20 or SEQ ID NO: 21.

Embodiment 172. The CDR3 scaffold of Embodiment 142, wherein the CDR3scaffold comprises a sequence derived from or based on SEQ ID NO: 22,SEQ ID NO: 23, SEQ ID NO: 24, SEQ ID NO: 25, SEQ ID NO: 26, SEQ ID NO:27, or SEQ ID NO: 28.

Embodiment 173. The CDR3 scaffold of Embodiment 142, wherein the CDR3scaffold is a ruminant CDR3 scaffold.

Embodiment 174. The CDR3 scaffold of Embodiment 173, wherein theruminant is a cow.

Embodiment 175. A library comprising the CDR3 scaffold of any one ofEmbodiments 142-174.

Embodiment 176. A polynucleotide encoding the CDR3 scaffold of any oneof Embodiments 142-174.

Embodiment 177. A vector comprising the polynucleotide of Embodiment176.

Embodiment 178. A host cell comprising the vector of Embodiment 177.

Embodiment 179. The host cell of Embodiment 178, wherein the cell is abacteria, virus, or bacteriophage.

For the disclosure herein, the very least, and not as an attempt tolimit the application of the doctrine of equivalents to the scope of theclaims, each numerical parameter should at least be construed in lightof the number of reported significant digits and by applying ordinaryrounding techniques. Notwithstanding that the numerical ranges andparameters setting forth the broad scope of the disclosure areapproximations, the numerical values set forth in the specific examplesare reported as precisely as possible. Any numerical value, however,inherently contains certain errors necessarily resulting from thestandard deviation found in their respective testing measurements.

The terms “a,” “an,” “the” and similar referents used in the context ofdescribing the exemplary embodiments (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. Recitation of ranges of values herein is merely intended toserve as a shorthand method of referring individually to each separatevalue falling within the range. Unless otherwise indicated herein, eachindividual value is incorporated into the specification as if it wereindividually recited herein. All methods described herein can beperformed in any suitable order unless otherwise indicated herein orotherwise clearly contradicted by context. The use of any and allexamples, or exemplary language (e.g., “such as”) provided herein isintended merely to better illuminate the exemplary embodiments and doesnot pose a limitation on the scope of the exemplary embodimentsotherwise claimed. No language in the specification should be construedas indicating any non-claimed element essential to the practice of theexemplary embodiments.

Groupings of alternative elements or embodiments disclosed herein arenot to be construed as limitations. Each group member can be referred toand claimed individually or in any combination with other members of thegroup or other elements found herein. It is anticipated that one or moremembers of a group can be included in, or deleted from, a group forreasons of convenience and/or patentability. When any such inclusion ordeletion occurs, the specification is deemed to contain the group asmodified thus fulfilling the written description of all Markush groupsused in the appended claims.

Certain embodiments are described herein, including the best mode knownto the inventors for carrying out the exemplary embodiments. Of course,variations on these described embodiments will become apparent to thoseof ordinary skill in the art upon reading the foregoing description. Theinventor expects skilled artisans to employ such variations asappropriate, and the inventors intend for the embodiments to bepracticed otherwise than specifically described herein. Accordingly,this disclosure includes all modifications and equivalents of thesubject matter recited in the claims appended hereto as permitted byapplicable law. Moreover, any combination of the above-describedelements in all possible variations thereof is encompassed by thedisclosure unless otherwise indicated herein or otherwise clearlycontradicted by context.

Furthermore, numerous references have been made to patents and printedpublications. Each of the above-cited references is individuallyincorporated herein by reference in their entirety.

Specific embodiments disclosed herein can be further limited in theclaims using consisting of or and consisting essentially of language.When used in the claims, whether as filed or added per amendment, thetransition term “consisting of” excludes any element, step, oringredient not specified in the claims. The transition term “consistingessentially of” limits the scope of a claim to the specified materialsor steps and those that do not materially affect the basic and novelcharacteristic(s). Exemplary embodiments so claimed are inherently orexpressly described and enabled herein.

In closing, it is to be understood that the exemplary embodimentsdisclosed herein are illustrative of the principles of the presentdisclosure. Other modifications that can be employed are within thescope of the disclosure. Thus, by way of example, but not of limitation,alternative configurations of the present exemplary embodiments can beutilized in accordance with the teachings herein. Accordingly, thepresent exemplary embodiments are not limited to that precisely as shownand described.

1. A humanized antibody or binding fragment thereof comprising anultralong CDR3.
 2. The humanized antibody or binding fragment thereof ofclaim 1, wherein the ultralong CDR3 is 35 amino acids in length orlonger, 40 amino acids in length or longer, 45 amino acids in length orlonger, 50 amino acids in length or longer, 55 amino acids in length orlonger, or 60 amino acids in length or longer.
 3. The humanized antibodyor binding fragment thereof of claim 2, wherein the ultralong CDR3 is 35amino acids in length or longer.
 4. The humanized antibody or bindingfragment thereof of claim 1, wherein the ultralong CDR3 comprises 3 ormore cysteine residues, 4 or more cysteine residues, 5 or more cysteineresidues, 6 or more cysteine residues, 7 or more cysteine residues, 8 ormore cysteine residues, 9 or more cysteine residues, 10 or more cysteineresidues, 11 or more cysteine residues, or 12 or more cysteine residues.5. The humanized antibody or binding fragment thereof of claim 4,wherein the ultralong CDR3 comprises 3 or more cysteine residues.
 6. Thehumanized antibody or binding fragment thereof of claim 1, wherein theantibodies or binding fragments thereof comprise a cysteine motif. 7.The humanized antibody or binding fragment thereof of claim 6, whereinthe cysteine motif is selected from the group consisting of:(SEQ ID NO: 41) CX₁₀CX₅CX₅CXCX₇C, (SEQ ID NO: 42) CX₁₀CX₆CX₅CXCX₁₅C, (SEQ ID NO: 43) CX₁₁CXCX₅C, (SEQ ID NO: 44) CX₁₁CX₅CX₅CXCX₇C, (SEQ ID NO: 45) CX₁₀CX₆CX₅CXCX₁₃C, (SEQ ID NO: 46) CX₁₀CX₅CXCX₄CX₈C, (SEQ ID NO: 47) CX₁₀CX₆CX₆CXCX₇C, (SEQ ID NO: 48) CX₁₀CX₄CX₇CXCX₈C, (SEQ ID NO: 49) CX₁₀CX₄CX₇CXCX₇C, (SEQ ID NO: 50) CX₁₃CX₈CX₈C, (SEQ ID NO: 51) CX₁₀CX₆CX₅CXCX₇C, (SEQ ID NO: 52) CX₁₀CX₅CX₅C, (SEQ ID NO: 53) CX₁₀CX₅CX₆CXCX₇C, (SEQ ID NO: 54) CX₁₀CX₆CX₅CX₇CX₈C, (SEQ ID NO: 55) CX₉CX₇CX₅CXCX₇C, (SEQ ID NO: 56) CX₁₀CX₆CX₅CXCX₈C, (SEQ ID NO: 57) CX₁₀CXCX₄CX₅CX₁₁C, (SEQ ID NO: 58)CX₇CX₃CX₆CX₅CXCX₅CX₁₀C,  (SEQ ID NO: 59) CX₁₀CXCX₄CX₅CXCX₂CX₃C, (SEQ ID NO: 60) CX₁₆CX₅CXC,  (SEQ ID NO: 61) CX₆CX₄CXCX₄CX₅C,(SEQ ID NO: 62) CX₁₁CX₄CX₅CX₆CX₃C,  (SEQ ID NO: 63) CX₈CX₂CX₆CX₅C,(SEQ ID NO: 64) CX₁₀CX₅CX₅CXCX₁₀C,  (SEQ ID NO: 65) CX₁₀CXCX₆CX₄CXC,(SEQ ID NO: 66) CX₁₀CX₅CX₅CXCX₂C,  (SEQ ID NO: 67) CX₁₄CX₂CX₃CXCXC,(SEQ ID NO: 68) CX₁₅CX₅CXC,  (SEQ ID NO: 69) CX₄CX₆CX₉CX₂CX₁₁C,(SEQ ID NO: 70) CX₆CX₄CX₅CX₅CX₁₂C,  (SEQ ID NO: 71)CX₇CX₃CXCXCX₄CX₅CX₉C,  (SEQ ID NO: 72) CX₁₀CX₆CX₅C,  (SEQ ID NO: 73)CX₇CX₃CX₅CX₅CX₉C, (SEQ ID NO: 74) CX₇CX₅CXCX₂C, (SEQ ID NO: 75)CX₁₉CXCX₆C, (SEQ ID NO: 76) CX₁₀CX₃CX₃CX₅CX₇CXCX₆C,  (SEQ ID NO: 77)CX₁₉CX₄CX₅CX₁₂CX₂C,  (SEQ ID NO: 78) CX₁₂CX₄CX₅CXCXCX₉CX₃C, (SEQ ID NO: 79) CX₁₂CX₄CX₅CX₁₂CX₂C,  (SEQ ID NO: 80) CX₁₉CX₆CX₅CXCX₁₁C, (SEQ ID NO: 81) CX₁₆CX₅CXCXCX₁₄C,  (SEQ ID NO: 82) CX₁₉CX₅CXCX₈CX₆C, (SEQ ID NO: 83) CX₁₂CX₄CX₅CX₈CX₂C, (SEQ ID NO: 84) CX₁₂CX₅CX₅CXCX₈C, (SEQ ID NO: 85) CX₁₉CX₆CX₅CXCX₄CXCX₉C,  (SEQ ID NO: 86)CX₁₁CX₄CX₅CX₈CX₂C,  (SEQ ID NO: 87) CX₁₉CX₆CX₅CX₈CX₂C,  (SEQ ID NO: 88)CX₁₉CX₆CX₅CXCX₈C,  (SEQ ID NO: 89) CX₁₉CX₆CX₅CXCX₃CX₈CX₂C, (SEQ ID NO: 90) CX₁₉CX₆CX₅CX₃CX₈C,  (SEQ ID NO: 91)CX₁₉CX₆CX₅CXCX₂CX₆CX₅C,  (SEQ ID NO: 92) CX₇CX₆CX₃CX₃CX₉C, (SEQ ID NO: 93) CX₉CX₈CX₅CX₆CX₅C, (SEQ ID NO: 94)CX₁₀CX₂CX₂CX₇CXCX₁₁CX₅C, and (SEQ ID NO: 95) CX₁₀CX₆CX₅CXCX₂CX₈CX₄C.


8. The humanized antibody or binding fragment thereof of claim 6,wherein the cysteine motif is selected from the group consisting of:(SEQ ID NO: 96) CCX₃CXCX₃CX₂CCXCX₅CX₉CX₅CXC, (SEQ ID NO: 97)CX₆CX₂CX₅CX₄CCXCX₄CX₆CXC, (SEQ ID NO: 98) CX₇CXCX₅CX₄CCCX₄CX₆CXC, (SEQ ID NO: 99) CX₉CX₃CXCX₂CXCCCX₆CX₄C,  (SEQ ID NO: 100)CX₆CX₃CXCX₄CX₄CCX₁₉CX₂CC, (SEQ ID NO: 101) CX₆CXCX₁CXCX₃CCX₃CX₄CX₁₀C, (SEQ ID NO: 102) CX₉CCCX₃CX₄CCCX₅CX₆C,  (SEQ ID NO: 103)CCX₈CX₆CX₄CX₃CX₄CCXCX₁C, (SEQ ID NO: 104) CCX₆CCX₅CCCX₄CX₄CX₁₂C, (SEQ ID NO: 105) CX₆CX₂CX₃CCCX₄CX₅CX₃CX₃C,  (SEQ ID NO: 106)CX₃CX₅CX₆CX₄CCXCX₅CX₄CXC, (SEQ ID NO: 107) CX₄CX₄CCX₄CX₄CXCX₁₁CX₂CXC, (SEQ ID NO: 108) CX₅CX₂CCX₅CX₄CCX₃CCX₇C,  (SEQ ID NO: 109)CX₅CX₅CX₃CX₂CXCCX₄CX₇CXC, (SEQ ID NO: 110) CX₃CX₇CX₃CX₄CCXCX₂CX₅CX₂C, (SEQ ID NO: 111) CX₉CX₃CXCX₄CCX₅CCCX₆C,  (SEQ ID NO: 112)CX₉CX₃CXCX₂CXCCX₆CX₃CX₃C, (SEQ ID NO: 113) CX₈CCXCX₃CCX₃CXCX₃CX₄C, (SEQ ID NO: 114) CX₉CCX₄CX₂CXCCXCX₄CX₃C,  (SEQ ID NO: 115)CX₁₀CXCX₃CX₂CXCCX₄CX₆CXC, (SEQ ID NO: 116) CX₉CXCX₃CX₂CXCCX₄CX₅CXC, (SEQ ID NO: 117) CX₆CCXCX₅CX₄CCXCX₅CX₂C,  (SEQ ID NO: 118)CX₆CCXCX₃CXCCX₃CX₄CC, (SEQ ID NO: 119) CX₆CCXCX₃CXCX₂CXCX₄CX₈C, (SEQ ID NO: 120) CX₄CX₂CCX₃CXCX₄CCX₂CX₃C,  (SEQ ID NO: 121)CX₃CX₅CX₃CCCX₄CX₉C, (SEQ ID NO: 122) CCX₉CX₃CXCCX₃CX₅C, (SEQ ID NO: 123) CX₉CX₂CX₃CX₄CCX₄CX₅C,  (SEQ ID NO: 124)CX₉CX₇CX₄CCXCX₇CX₃C,  (SEQ ID NO: 125) CX₉CX₃CCCX₁₀CX₂CX₃C, (SEQ ID NO: 126) CX₃CX₅CX₅CX₄CCX₁₀CX₆C, (SEQ ID NO: 127)CX₉CX₅CX₄CCXCX₅CX₄C,  (SEQ ID NO: 128) CX₇CXCX₆CX₄CCCX₁₉C, (SEQ ID NO: 129) CX₉CX₂CX₄CCX₄CX₃CX₃C,  (SEQ ID NO: 130)CX₇CX₅CXCX₄CCX₇CX₄C, (SEQ ID NO: 131) CX₁₁CX₃CX₄CCCX₉CX₂C,(SEQ ID NO: 132) CX₂CX₃CX₄CCX₄CX₅CX₁₅C,  (SEQ ID NO: 133)CX₉CX₅CX₄CCX₇C,  (SEQ ID NO: 134) CX₉CX₇CX₃CX₂CX₆C,  (SEQ ID NO: 135)CX₉CX₅CX₄CCX₁₄C,  (SEQ ID NO: 136) CX₉CX₅CX₄CCX₉C,  (SEQ ID NO: 137)CX₉CX₆CX₄CCXC, (SEQ ID NO: 138) CX₅CCX₇CX₄CX₁₂,  (SEQ ID NO: 139)CX₁₀CX₃CX₄CCX₄C, (SEQ ID NO: 140) CX₉CX₄CCX₅CX₄C,  (SEQ ID NO: 141)CX₁₀CX₃CX₄CX₇CXC, (SEQ ID NO: 142) CX₇CX₇CX₂CX₂CX₃C,  (SEQ ID NO: 143)CX₉CX₄CX₄CCX₆C, (SEQ ID NO: 144) CX₇CXCX₃CXCX₆C,  (SEQ ID NO: 145)CX₇CXCX₄CXCX₄C, (SEQ ID NO: 146) CX₉CX₅CX₄C,  (SEQ ID NO: 147)CX₃CX₆CX₉C,  (SEQ ID NO: 148) CX₁₀CXCX₄C,  (SEQ ID NO: 149) CX₁₀CCX₄C, (SEQ ID NO: 150) CX₁₅C,  (SEQ ID NO: 151) CX₁₀C,  and  (SEQ ID NO: 152)CX₉C.


9. The humanized antibody or binding fragment thereof of claim 1,wherein the ultralong CDR3 comprises 2 to 6 disulfide bonds.
 10. Thehumanized antibody or binding fragment thereof of claim 1, wherein theultralong CDR3 comprises SEQ ID NO: 40 or a derivative thereof.
 11. Thehumanized antibody or binding fragment thereof of claim 1, wherein theultralong CDR3 comprises amino acid residues 3-6 of any of one SEQ IDNO: 1-4.
 12. The humanized antibody or binding fragment thereof of claim1, wherein the ultralong CDR3 comprises a non-human DH or a derivativethereof.
 13. The humanized antibody or binding fragment thereof of claim12, wherein the non-human DH is SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO:7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, or SEQ IDNO:
 12. 14. The humanized antibody or binding fragment thereof of claim1, wherein the ultralong CDR3 comprises a JH sequence or a derivativethereof.
 15. The humanized antibody or binding fragment thereof of claim14, wherein the JH sequence is SEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO:15, SEQ ID NO: 16, or SEQ ID NO:
 17. 16. The humanized antibody orbinding fragment thereof of claim 1, wherein the ultralong CDR3comprises: a non-human VH sequence or a derivative thereof; a non-humanDH sequence or a derivative thereof; and/or a JH sequence or derivativethereof.
 17. The humanized antibody or binding fragment thereof of claim16, wherein the ultralong CDR3 comprises an additional amino acidsequence comprising two to six amino acid residues or more positionedbetween the VH sequence and the DH sequence.
 18. The humanized antibodyor binding fragment thereof of claim 17, wherein the additional aminoacid sequence is selected from the group consisting of: IR, IF, SEQ IDNO: 18, SEQ ID NO: 19, SEQ ID NO: 20 or SEQ ID NO:
 21. 19. The humanizedantibody or binding fragment thereof of claim 1, wherein the ultralongCDR3 comprises a sequence derived from or based on SEQ ID NO: 22, SEQ IDNO: 23, SEQ ID NO: 24, SEQ ID NO: 25, SEQ ID NO: 26, SEQ ID NO: 27, orSEQ ID NO:
 28. 20. The humanized antibody or binding fragment thereof ofclaim 1, wherein the ultralong CDR3 comprises a non-bovine sequence or anon-antibody sequence.
 21. The humanized antibody or binding fragmentthereof of claim 20, wherein the non-antibody sequence is a syntheticsequence.
 22. The humanized antibody or binding fragment thereof ofclaim 20, wherein the non-antibody sequence is a cytokine sequence, alymphokine sequence, a chemokine sequence, a growth factor sequence, ahormone sequence, or a toxin sequence.
 23. The humanized antibody orbinding fragment thereof of claim 20, wherein the non-antibody sequenceis an IL-8 sequence, an IL-21 sequence, an SDF-1 (alpha) sequence, asomatostatin sequence, a chlorotoxin sequence, a Pro-TxII sequence, or aziconotide sequence.
 24. The humanized antibody or binding fragmentthereof of claim 20, wherein the non-antibody sequence is any one of SEQID NOS: 475-481.
 25. The humanized antibody or binding fragment thereofof claim 20, wherein the non-antibody sequence replaces at least aportion of the ultralong CDR3.
 26. The humanized antibody or bindingfragment thereof of claim 1, wherein the ultralong CDR3 comprises aX¹X²X³X⁴X⁵ motif, wherein X¹ is threonine (T), glycine (G), alanine (A),serine (S), or valine (V), wherein X² is serine (S), threonine (T),proline (P), isoleucine (I), alanine (A), valine (V), or asparagine (N),wherein X³ is valine (V), alanine (A), threonine (T), or aspartic acid(D), wherein X⁴ is histidine (H), threonine (T), arginine (R), tyrosine(Y), phenylalanine (F), or leucine (L), and wherein X⁵ is glutamine (Q).27. The humanized antibody or binding fragment thereof of claim 26,wherein the X¹X²X³X⁴X⁵ motif is TTVHQ (SEQ ID NO: 153), TSVHQ (SEQ IDNO: 154), SSVTQ (SEQ ID NO: 155), STVHQ (SEQ ID NO: 156), ATVRQ (SEQ IDNO: 157), TTVYQ (SEQ ID NO: 158), SPVHQ (SEQ ID NO: 159), ATVYQ (SEQ IDNO: 160), TAVYQ (SEQ ID NO: 161), TNVHQ (SEQ ID NO: 162), ATVHQ (SEQ IDNO: 163), STVYQ (SEQ ID NO: 164), TIVHQ (SEQ ID NO: 165), AIVYQ (SEQ IDNO: 166), TTVFQ (SEQ ID NO: 167), AAVFQ (SEQ ID NO: 168), GTVHQ (SEQ IDNO: 169), ASVHQ (SEQ ID NO: 170), TAVFQ (SEQ ID NO: 171), ATVFQ (SEQ IDNO: 172), AAAHQ (SEQ ID NO: 173), VVVYQ (SEQ ID NO: 174), GTVFQ (SEQ IDNO: 175), TAVHQ (SEQ ID NO: 176), ITVHQ (SEQ ID NO: 177), ITAHQ (SEQ IDNO: 178), VTVHQ (SEQ ID NO: 179); AAVHQ (SEQ ID NO: 180), GTVYQ (SEQ IDNO: 181), TTVLQ (SEQ ID NO: 182), TTTHQ (SEQ ID NO: 183), or TTDYQ (SEQID NO: 184).
 28. The humanized antibody or binding fragment thereof ofclaim 1, wherein the ultralong CDR3 comprises a CX¹X²X³X⁴X⁵ motif. 29.The humanized antibody or binding fragment thereof of claim 28, whereinthe CX¹X²X³X⁴X⁵ motif is CTTVHQ (SEQ ID NO: 185), CTSVHQ (SEQ ID NO:186), CSSVTQ (SEQ ID NO: 187), CSTVHQ (SEQ ID NO: 188), CATVRQ (SEQ IDNO: 189), CTTVYQ (SEQ ID NO: 190), CSPVHQ (SEQ ID NO: 191), CATVYQ (SEQID NO: 192), CTAVYQ (SEQ ID NO: 193), CTNVHQ (SEQ ID NO: 194), CATVHQ(SEQ ID NO: 195), CSTVYQ (SEQ ID NO: 196), CTIVHQ (SEQ ID NO: 197),CAIVYQ (SEQ ID NO: 198), CTTVFQ (SEQ ID NO: 199), CAAVFQ (SEQ ID NO:200), CGTVHQ (SEQ ID NO: 201), CASVHQ (SEQ ID NO: 202), CTAVFQ (SEQ IDNO: 203), CATVFQ (SEQ ID NO: 204), CAAAHQ (SEQ ID NO: 205), CVVVYQ (SEQID NO: 206), CGTVFQ (SEQ ID NO: 207), CTAVHQ (SEQ ID NO: 208), CITVHQ(SEQ ID NO: 209), CITAHQ (SEQ ID NO: 210), CVTVHQ (SEQ ID NO: 211);CAAVHQ (SEQ ID NO: 212), CGTVYQ (SEQ ID NO: 213), CTTVLQ (SEQ ID NO:214), CTTTHQ (SEQ ID NO: 215), or CTTDYQ (SEQ ID NO: 216).
 30. Thehumanized antibody or binding fragment thereof of claim 1, wherein theultralong CDR3 comprises a (X^(a)X^(b))_(z) motif, wherein X^(a) is anyamino acid residue, X^(b) is an aromatic amino acid selected from thegroup consisting of: tyrosine (Y), phenylalanine (F), tryptophan (W),and histidine (H), and wherein z is 1-4.
 31. The humanized antibody orbinding fragment thereof of claim 30, wherein the (X^(a)X^(b))_(z) motifis CYTYNYEF (SEQ ID NO: 217), HYTYTYDF (SEQ ID NO: 218), HYTYTYEW (SEQID NO: 219), KHRYTYEW (SEQ ID NO: 220), NYIYKYSF (SEQ ID NO: 221),PYIYTYQF (SEQ ID NO: 222), SFTYTYEW (SEQ ID NO: 223), SYIYIYQW (SEQ IDNO: 224), SYNYTYSW (SEQ ID NO: 225), SYSYSYEY (SEQ ID NO: 226), SYTYNYDF(SEQ ID NO: 227), SYTYNYEW (SEQ ID NO: 228), SYTYNYQF (SEQ ID NO: 229),SYVWTHNF (SEQ ID NO: 230), TYKYVYEW (SEQ ID NO: 231), TYTYTYEF (SEQ IDNO: 232), TYTYTYEW (SEQ ID NO: 233), VFTYTYEF (SEQ ID NO: 234), AYTYEW(SEQ ID NO: 235), DYIYTY (SEQ ID NO: 236), IHSYEF (SEQ ID NO: 237),SFTYEF (SEQ ID NO: 238), SHSYEF (SEQ ID NO: 239), THTYEF (SEQ ID NO:240), TWTYEF (SEQ ID NO: 241), TYNYEW (SEQ ID NO: 242), TYSYEF (SEQ IDNO: 243), TYSYEH (SEQ ID NO: 244), TYTYDF (SEQ ID NO: 245), TYTYEF (SEQID NO: 246), TYTYEW (SEQ ID NO: 247), AYEF (SEQ ID NO: 248), AYSF (SEQID NO: 249), AYSY (SEQ ID NO: 250), CYSF (SEQ ID NO: 251), DYTY (SEQ IDNO: 252), KYEH (SEQ ID NO: 253), KYEW (SEQ ID NO: 254), MYEF (SEQ ID NO:255), NWIY (SEQ ID NO: 256), NYDY (SEQ ID NO: 257), NYQW (SEQ ID NO:258), NYSF (SEQ ID NO: 259), PYEW (SEQ ID NO: 260), RYNW (SEQ ID NO:261), RYTY (SEQ ID NO: 262), SYEF (SEQ ID NO: 263), SYEH (SEQ ID NO:264), SYEW (SEQ ID NO: 265), SYKW (SEQ ID NO: 266), SYTY (SEQ ID NO:267), TYDF (SEQ ID NO: 268), TYEF (SEQ ID NO: 269), TYEW (SEQ ID NO:270), TYQW (SEQ ID NO: 271), TYTY (SEQ ID NO: 272), or VYEW (SEQ ID NO:273).
 32. The humanized antibody or binding fragment thereof of claim30, wherein the (X^(a)X^(b))_(z) motif is YXYXYX.
 33. The humanizedantibody or binding fragment thereof of claim 1, wherein the ultralongCDR3 comprises a X¹X²X³X⁴X⁵X_(n) motif, wherein X₁ is threonine (T),glycine (G), alanine (A), serine (S), or valine (V), wherein X₂ isserine (S), threonine (T), proline (P), isoleucine (I), alanine (A),valine (V), or asparagine (N), wherein X₃ is valine (V), alanine (A),threonine (T), or aspartic acid (D), wherein X₄ is histidine (H),threonine (T), arginine (R), tyrosine (Y), phenylalanine (F), or leucine(L), wherein X₅ is glutamine (Q), and wherein n is 27-54.
 34. Thehumanized antibody or binding fragment thereof of claim 1, wherein theultralong CDR3 comprises X_(n)(X^(a)X^(b))_(z) motif, wherein X^(a) isany amino acid residue, X^(b) is an aromatic amino acid selected fromthe group consisting of: tyrosine (Y), phenylalanine (F), tryptophan(W), and histidine (H), wherein n is 27-54, and wherein z is 1-4. 35.The humanized antibody or binding fragment thereof of claim 1, whereinthe ultralong CDR3 comprises a X¹X²X³X⁴X⁵X_(n)(X^(a)X^(b))_(z) motif,wherein X¹ is threonine (T), glycine (G), alanine (A), serine (S), orvaline (V), wherein X² is serine (S), threonine (T), proline (P),isoleucine (I), alanine (A), valine (V), or asparagine (N), wherein X³is valine (V), alanine (A), threonine (T), or aspartic acid (D), whereinX⁴ is histidine (H), threonine (T), arginine (R), tyrosine (Y),phenylalanine (F), or leucine (L), and wherein X⁵ is glutamine (Q),wherein X^(a) is any amino acid residue, X^(b) is an aromatic amino acidselected from the group consisting of: tyrosine (Y), phenylalanine (F),tryptophan (W), and histidine (H), wherein n is 27-54, and wherein z is1-4.
 36. The humanized antibody or binding fragment thereof of claim 35,wherein the X¹X²X³X⁴X⁵ motif is TTVHQ (SEQ ID NO: 153) or TSVHQ (SEQ IDNO: 154), and wherein the (X^(a)X^(b))_(z) motif is YXYXYX.
 37. Thehumanized antibody or binding fragment thereof of claim 1, wherein theultralong CDR3 comprises: a CX¹X²X³X⁴X⁵ motif, wherein X¹ is threonine(T), glycine (G), alanine (A), serine (S), or valine (V), wherein X² isserine (S), threonine (T), proline (P), isoleucine (I), alanine (A),valine (V), or asparagine (N), wherein X³ is valine (V), alanine (A),threonine (T), or aspartic acid (D), wherein X⁴ is histidine (H),threonine (T), arginine (R), tyrosine (Y), phenylalanine (F), or leucine(L), and wherein X⁵ is glutamine (Q), a cysteine motif selected from thegroup consisting of: CX₁₀CX₅CX₅CXCX₇C (SEQ ID NO: 41), CX₁₀CX₆CX₅CXCX₁₅C(SEQ ID NO: 42), CX₁₁CXCX₅C (SEQ ID NO: 43), CX₁₁CX₅CX₅CXCX₇C (SEQ IDNO: 44), CX₁₀CX₆CX₅CXCX₁₃C (SEQ ID NO: 45), CX₁₀CX₅CXCX₄CX₈C (SEQ ID NO:46), CX₁₀CX₆CX₆CXCX₇C (SEQ ID NO: 47), CX₁₀CX₄CX₇CXCX₈C (SEQ ID NO: 48),CX₁₀CX₄CX₇CXCX₇C (SEQ ID NO: 49), CX₁₃CX₈CX₈C (SEQ ID NO: 50),CX₁₀CX₆CX₅CXCX₇C (SEQ ID NO: 51), CX₁₀CX₅CX₅C (SEQ ID NO: 52),CX₁₀CX₅CX₆CXCX₇C (SEQ ID NO: 53), CX₁₀CX₆CX₅CX₇CX₉C (SEQ ID NO: 54),CX₉CX₇CX₅CXCX₇C (SEQ ID NO: 55), CX₁₀CX₆CX₅CXCX₉C (SEQ ID NO: 56),CX₁₀CXCX₄CX₅CX₁₁C (SEQ ID NO: 57), CX₇CX₃CX₆CX₅CXCX₅CX₁₀C (SEQ ID NO:58), CX₁₀CXCX₄CX₅CXCX₂CX₃C (SEQ ID NO: 59), CX₁₆CX₅CXC (SEQ ID NO: 60),CX₆CX₄CXCX₄CX₅C (SEQ ID NO: 61), CX₁₁CX₄CX₅CX₆CX₃C (SEQ ID NO: 62),CX₈CX₂CX₆CX₅C (SEQ ID NO: 63), CX₁₀CX₅CX₅CXCX₁₀C (SEQ ID NO: 64),CX₁₀CXCX₆CX₄CXC (SEQ ID NO: 65), CX₁₀CX₅CX₅CXCX₂C (SEQ ID NO: 66),CX₁₄CX₂CX₃CXCXC (SEQ ID NO: 67), CX₁₅CX₅CXC (SEQ ID NO: 68),CX₄CX₆CX₉CX₂CX₁₁C (SEQ ID NO: 69), CX₆CX₄CX₅CX₅CX₁₂C (SEQ ID NO: 70),CX₇CX₃CXCXCX₄CX₅CX₉C (SEQ ID NO: 71), CX₁₀CX₆CX₅C (SEQ ID NO: 72),CX₇CX₃CX₅CX₅CX₉C (SEQ ID NO: 73), CX₇CX₅CXCX₂C (SEQ ID NO: 74),CX₁₀CXCX₆C (SEQ ID NO: 75), CX₁₀CX₃CX₃CX₅CX₇CXCX₆C (SEQ ID NO: 76),CX₁₀CX₄CX₅CX₁₂CX₂C (SEQ ID NO: 77), CX₁₂CX₄CX₅CXCXCX₉CX₃C (SEQ ID NO:78), CX₁₂CX₄CX₅CX₁₂CX₂C (SEQ ID NO: 79), CX₁₀CX₆CX₅CXCX₁₁C (SEQ ID NO:80), CX₁₆CX₅CXCXCX₁₄C (SEQ ID NO: 81), CX₁₀CX₅CXCX₈CX₆C (SEQ ID NO: 82),CX₁₂CX₄CX₅CX₈CX₂C (SEQ ID NO: 83), CX₁₂CX₅CX₅CXCX₈C (SEQ ID NO: 84),CX₁₀CX₆CX₅CXCX₄CXCX₉C (SEQ ID NO: 85), CX₁₁CX₄CX₅CX₈CX₂C (SEQ ID NO:86), CX₁₀CX₆CX₅CX₈CX₂C (SEQ ID NO: 87), CX₁₀CX₆CX₅CXCX₈C (SEQ ID NO:88), CX₁₀CX₆CX₅CXCX₃CX₈CX₂C (SEQ ID NO: 89), CX₁₀CX₆CX₅CX₃CX₈C (SEQ IDNO: 90), CX₁₀CX₆CX₅CXCX₂CX₆CX₅C (SEQ ID NO: 91), CX₇CX₆CX₃CX₃CX₉C (SEQID NO: 92), CX₉CX₈CX₅CX₆CX₅C (SEQ ID NO: 93), CX₁₀CX₂CX₂CX₇CXCX₁₁CX₅C(SEQ ID NO: 94), and CX₁₀CX₆CX₅CXCX₂CX₈CX₄C (SEQ ID NO: 95), a(X^(a)X^(b))_(z) motif, wherein X^(a) is any amino acid residue, X^(b)is an aromatic amino acid selected from the group consisting of:tyrosine (Y), phenylalanine (F), tryptophan (W), and histidine (H), andwherein z is 1-4.
 38. The humanized antibody or binding fragment thereofof claim 1, wherein the ultralong CDR3 comprises: a CX¹X²X³X⁴X⁵ motif,wherein X¹ is threonine (T), glycine (G), alanine (A), serine (S), orvaline (V), wherein X² is serine (S), threonine (T), proline (P),isoleucine (I), alanine (A), valine (V), or asparagine (N), wherein X³is valine (V), alanine (A), threonine (T), or aspartic acid (D), whereinX⁴ is histidine (H), threonine (T), arginine (R), tyrosine (Y),phenylalanine (F), or leucine (L), and wherein X⁵ is glutamine (Q); acysteine motif selected from the group consisting of: wherein thecysteine motif is selected from the group consisting of:CCX₃CXCX₃CX₂CCXCX₅CX₉CX₅CXC (SEQ ID NO: 96), CX₆CX₂CX₅CX₄CCXCX₄CX₆CXC(SEQ ID NO: 97), CX₇CXCX₅CX₄CCCX₄CX₆CXC (SEQ ID NO: 98),CX₉CX₃CXCX₂CXCCCX₆CX₄C (SEQ ID NO: 99), CX₅CX₃CXCX₄CX₄CCX₁₀CX₂CC (SEQ IDNO: 100), CX₅CXCX₁CXCX₃CCX₃CX₄CX₁₀C (SEQ ID NO: 101),CX₉CCCX₃CX₄CCCX₅CX₆C (SEQ ID NO: 102), CCX₈CX₅CX₄CX₃CX₄CCXCX₁C (SEQ IDNO: 103), CCX₆CCX₅CCCX₄CX₄CX₁₂C (SEQ ID NO: 104),CX₆CX₂CX₃CCCX₄CX₅CX₃CX₃C (SEQ ID NO: 105), CX₃CX₅CX₆CX₄CCXCX₅CX₄CXC (SEQID NO: 106), CX₄CX₄CCX₄CX₄CXCX₁₁CX₂CXC (SEQ ID NO: 107),CX₅CX₂CCX₅CX₄CCX₃CCX₇C (SEQ ID NO: 108), CX₅CX₅CX₃CX₂CXCCX₄CX₇CXC (SEQID NO: 109), CX₃CX₇CX₃CX₄CCXCX₂CX₅CX₂C (SEQ ID NO: 110),CX₉CX₃CXCX₄CCX₅CCCX₆C (SEQ ID NO: 111), CX₉CX₃CXCX₂CXCCX₆CX₃CX₃C (SEQ IDNO: 112), CX₈CCXCX₃CCX₃CXCX₃CX₄C (SEQ ID NO: 113),CX₉CCX₄CX₂CXCCXCX₄CX₃C (SEQ ID NO: 114), CX₁₀CXCX₃CX₂CXCCX₄CX₅CXC (SEQID NO: 115), CX₉CXCX₃CX₂CXCCX₄CX₅CXC (SEQ ID NO: 116),CX₆CCXCX₅CX₄CCXCX₅CX₂C (SEQ ID NO: 117), CX₆CCXCX₃CXCCX₃CX₄CC (SEQ IDNO: 118), CX₆CCXCX₃CXCX₂CXCX₄CX₈C (SEQ ID NO: 119),CX₄CX₂CCX₃CXCX₄CCX₂CX₃C (SEQ ID NO: 120), CX₃CX₅CX₃CCCX₄CX₉C (SEQ ID NO:121), CCX₉CX₃CXCCX₃CX₅C (SEQ ID NO: 122), CX₉CX₂CX₃CX₄CCX₄CX₅C (SEQ IDNO: 123), CX₉CX₇CX₄CCXCX₇CX₃C (SEQ ID NO: 124), CX₉CX₃CCCX₁₀CX₂CX₃C (SEQID NO: 125), CX₃CX₅CX₅CX₄CCX₁₀CX₆C (SEQ ID NO: 126), CX₉CX₅CX₄CCXCX₅CX₄C(SEQ ID NO: 127), CX₇CXCX₆CX₄CCCX₁₀C (SEQ ID NO: 128),CX₈CX₂CX₄CCX₄CX₃CX₃C (SEQ ID NO: 129), CX₇CX₅CXCX₄CCX₇CX₄C (SEQ ID NO:130), CX₁₁CX₃CX₄CCCX₈CX₂C (SEQ ID NO: 131), CX₂CX₃CX₄CCX₄CX₅CX₁₅C (SEQID NO: 132), CX₉CX₅CX₄CCX₇C (SEQ ID NO: 133), CX₉CX₇CX₃CX₂CX₆C (SEQ IDNO: 134), CX₉CX₅CX₄CCX₁₄C (SEQ ID NO: 135), CX₉CX₅CX₄CCX₈C (SEQ ID NO:136), CX₉CX₆CX₄CCXC (SEQ ID NO: 137), CX₅CCX₇CX₄CX₁₂ (SEQ ID NO: 138),CX₁₀CX₃CX₄CCX₄C (SEQ ID NO: 139), CX₉CX₄CCX₅CX₄C (SEQ ID NO: 140),CX₁₀CX₃CX₄CX₇CXC (SEQ ID NO: 141), CX₇CX₇CX₂CX₂CX₃C (SEQ ID NO: 142),CX₉CX₄CX₄CCX₆C (SEQ ID NO: 143), CX₇CXCX₃CXCX₆C (SEQ ID NO: 144),CX₇CXCX₄CXCX₄C (SEQ ID NO: 145), CX₉CX₅CX₄C (SEQ ID NO: 146), CX₃CX₆CX₈C(SEQ ID NO: 147), CX₁₀CXCX₄C (SEQ ID NO: 148), CX₁₀CCX₄C (SEQ ID NO:149), CX₁₅C (SEQ ID NO: 150), CX₁₀C (SEQ ID NO: 151), and CX₉C (SEQ IDNO: 152); and a (X^(a)X^(b))_(z) motif, wherein X^(a) is any amino acidresidue, X^(b) is an aromatic amino acid selected from the groupconsisting of: tyrosine (Y), phenylalanine (F), tryptophan (W), andhistidine (H), and wherein z is 1-4.
 39. The humanized antibody orbinding fragment thereof of claim 20, wherein the ultralong CDR3comprises an additional sequence that is a linker.
 40. The humanizedantibody or binding fragment thereof of claim 39, wherein the linker islinked to a C-terminus, a N-terminus, or both C-terminus and N-terminusof the non-antibody sequence.
 41. The humanized antibody or bindingfragment thereof of claim 1, wherein the ultralong CDR3 is a ruminantCDR3.
 42. The humanized antibody or binding fragment thereof of claim41, wherein the ruminant is a cow.
 43. The humanized antibody or bindingfragment thereof of claim 1, wherein the humanized antibody or bindingfragment thereof comprises a human heavy chain germline sequence that isa VH4 family member germline sequence.
 44. The humanized antibody orbinding fragment thereof of claim 1, wherein the humanized antibody orbinding fragment thereof comprises a VH4-34 germline sequence.
 45. Thehumanized antibody or binding fragment thereof of claim 44, wherein thehumanized antibody or binding fragment thereof comprises a human heavychain germline sequence that is derived from the VH4-34 germlinesequence.
 46. The humanized antibody or binding fragment thereof ofclaim 45, wherein the VH4-34 germline sequence comprises a CDR1comprising a Gly31Asp and Tyr32Lys substitution based on Kabatnumbering.
 47. The humanized antibody or binding fragment thereof ofclaim 45, wherein the VH4-34 germline sequence comprises a CDR2comprising a Glu50Ser substitution based on Kabat numbering.
 48. Thehumanized antibody or binding fragment thereof of claim 45, wherein theVH4-34 germline sequence comprises a CDR1 comprising Ala23Thr, Val24Ala,Tyr25Ser, Gly27Phe, Phe29Leu, Gly31Asp, Tyr32Lys, Tyr33Ala, Trp34Val,and Ser35Gly substitutions, and a CDR2 comprising Ile48Leu, Glu50Ser,Asn52Asp, His53Thr, Ser54Gly, Ser56Asn, and Asn58Gly substitutions,based on Kabat numbering.
 49. The humanized antibody or binding fragmentthereof of claim 1, wherein the humanized antibody or binding fragmentthereof comprises the amino acid sequence set forth in SEQ ID NO: 461,462, 463, 464, 465, 466, 467, 468, or
 469. 50. The humanized antibody orbinding fragment thereof of claim 1, wherein the humanized antibody orbinding fragment thereof comprises the amino acid sequence set forth inSEQ ID NO:
 470. 51. The humanized antibody or binding fragment thereofof claim 1, wherein the humanized antibody or binding fragment thereofcomprises the amino acid sequence set forth in SEQ ID NO: 461, 462, 463,464, 465, 466, 467, 468, or 469; and the amino acid sequence set forthin SEQ ID NO:
 470. 52. The humanized antibody or binding fragmentthereof of claim 1, wherein the humanized antibody or binding fragmentthereof comprises the amino acid sequence set forth in SEQ ID NO: 461,462, 463, 464, 465, 466, 467, 468, or 469; the amino acid sequence setforth in SEQ ID NO: 470; and a peptide sequence, wherein the peptidesequence is positioned between SEQ ID NO: 461, 462, 463, 464, 465, 466,467, 468, or 469, and SEQ ID NO:
 470. 53. The humanized antibody orbinding fragment thereof of claim 52, wherein the peptide sequence is abovine sequence, a non-bovine sequence, an antibody sequence, or anon-antibody sequence.
 54. The humanized antibody or binding fragmentthereof of claim 1, wherein the humanized antibody or binding fragmentthereof comprises a light chain variable region sequence that is alambda light chain variable region sequence.
 55. The humanized antibodyor binding fragment thereof of claim 54, wherein the lambda light chainvariable region sequence is a bovine lambda light chain variable regionsequence.
 56. The humanized antibody or binding fragment thereof ofclaim 54, wherein the lambda light chain variable region sequence is ahuman lambda light chain variable region sequence.
 57. The humanizedantibody or binding fragment thereof of claim 56, wherein the humanlambda light chain variable region sequence is a VL1-51 germlinesequence.
 58. The humanized antibody or binding fragment thereof ofclaim 56, wherein the human lambda light chain variable region sequenceis derived from a VL1-51 germline sequence.
 59. The humanized antibodyor binding fragment thereof of claim 58, wherein the VL1-51 germlinesequence comprises a CDR1 comprising Ile29Val and Asn32Gly substitutionbased on Kabat numbering.
 60. The humanized antibody or binding fragmentthereof of claim 58, wherein the VL1-51 germline sequence comprises aCDR2 comprising a substitution of DNN to GDT.
 61. The humanized antibodyor binding fragment thereof of claim 58, wherein the VL1-51 germlinesequence comprises a CDR2 comprising a substitution of DNNKRP (SEQ IDNO: 471) to GDTSRA (SEQ ID NO: 472).
 62. The humanized antibody orbinding fragment thereof of claim 58, wherein the VL1-51 germlinesequence comprises a S2A, T5N, P8S, A12G, A13S, and P14L substitutionbased on Kabat numbering.
 63. The humanized antibody or binding fragmentthereof of claim 58, wherein the VL1-51 germline sequence comprises aS2A, T5N, P8S, A12G, A13S, and P14L substitution based on Kabatnumbering, and a CDR2 comprising a substitution of DNN to GDT.
 64. Thehumanized antibody or binding fragment thereof of claim 1, wherein thehumanized antibody or binding fragment thereof comprising the amino acidsequence set forth in SEQ ID NO: 440, 441, 442, 443, or
 444. 65. Apolynucleotide encoding the humanized antibody or binding fragmentthereof of any one of claims 1-64.
 66. A polynucleotide encoding ahumanized antibody or binding fragment thereof that comprises anultralong CDR3.
 67. A polynucleotide encoding a humanized variableregion that comprises an ultralong CDR3.
 68. A vector comprising thepolynucleotide of any one of claims 65-67.
 69. A host cell comprisingthe vector of claim
 68. 70. A nucleic acid library comprising aplurality of polynucleotides comprising sequences coding for humanizedantibodies or binding fragments thereof, wherein the antibodies orbinding fragments thereof comprise an ultralong CDR3.
 71. A library ofhumanized antibodies or binding fragments thereof, wherein theantibodies or binding fragments thereof comprise an ultralong CDR3. 72.The library of claim 71, wherein the ultralong CDR3 is 35 amino acids inlength or longer, 40 amino acids in length or longer, 45 amino acids inlength or longer, 50 amino acids in length or longer, 55 amino acids inlength or longer, or 60 amino acids in length or longer.
 73. The libraryof claim 72, wherein the ultralong CDR3 is 35 amino acids in length orlonger.
 74. The library of claim 71, wherein the ultralong CDR3comprises 3 or more cysteine residues, 4 or more cysteine residues, 5 ormore cysteine residues, 6 or more cysteine residues, 7 or more cysteineresidues, 8 or more cysteine residues, 9 or more cysteine residues, 10or more cysteine residues, 11 or more cysteine residues, or 12 or morecysteine residues.
 75. The library of claim 74, wherein the ultralongCDR3 comprises 3 or more cysteine residues.
 76. The library of claim 71,wherein the antibodies or binding fragments thereof comprise a cysteinemotif.
 77. The library of claim 76, wherein the cysteine motif isselected from the group consisting of: (SEQ ID NO: 41)CX₁₀CX₅CX₅CXCX₇C,  (SEQ ID NO: 42) CX₁₀CX₆CX₅CXCX₁₅C,  (SEQ ID NO: 43)CX₁₁CXCX₅C,  (SEQ ID NO: 44) CX₁₁CX₅CX₅CXCX₇C, (SEQ ID NO: 45)CX₁₀CX₆CX₅CXCX₁₃C,  (SEQ ID NO: 46) CX₁₀CX₅CXCX₄CX₈C, (SEQ ID NO: 47)CX₁₀CX₆CX₆CXCX₇C,  (SEQ ID NO: 48) CX₁₀CX₄CX₇CXCX₈C, (SEQ ID NO: 49)CX₁₀CX₄CX₇CXCX₇C,  (SEQ ID NO: 50) CX₁₃CX₈CX₈C, (SEQ ID NO: 51)CX₁₀CX₆CX₅CXCX₇C,  (SEQ ID NO: 52) CX₁₀CX₅CX₅C, (SEQ ID NO: 53)CX₁₀CX₅CX₆CXCX₇C,  (SEQ ID NO: 54) CX₁₀CX₆CX₅CX₇CX₈C, (SEQ ID NO: 55)CX₉CX₇CX₅CXCX₇C,  (SEQ ID NO: 56) CX₁₀CX₆CX₅CXCX₈C, (SEQ ID NO: 57)CX₁₀CXCX₄CX₅CX₁₁C,  (SEQ ID NO: 58) CX₇CX₃CX₆CX₅CXCX₅CX₁₀C, (SEQ ID NO: 59) CX₁₀CXCX₄CX₅CXCX₂CX₃C,  (SEQ ID NO: 60) CX₁₆CX₅CXC,(SEQ ID NO: 61) CX₆CX₄CXCX₄CX₅C,  (SEQ ID NO: 62) CX₁₁CX₄CX₅CX₆CX₃C,(SEQ ID NO: 63) CX₈CX₂CX₆CX₅C,  (SEQ ID NO: 64) CX₁₀CX₅CX₅CXCX₁₀C,(SEQ ID NO: 65) CX₁₀CXCX₆CX₄CXC,  (SEQ ID NO: 66) CX₁₀CX₅CX₅CXCX₂C,(SEQ ID NO: 67) CX₁₄CX₂CX₃CXCXC,  (SEQ ID NO: 68) CX₁₅CX₅CXC,(SEQ ID NO: 69) CX₄CX₆CX₉CX₂CX₁₁C,  (SEQ ID NO: 70) CX₆CX₄CX₅CX₅CX₁₂C,(SEQ ID NO: 71) CX₇CX₃CXCXCX₄CX₅CX₉C,  (SEQ ID NO: 72) CX₁₀CX₆CX₅C,(SEQ ID NO: 73) CX₇CX₃CX₅CX₅CX₉C,  (SEQ ID NO: 74) CX₇CX₅CXCX₂C,(SEQ ID NO: 75) CX₁₀CXCX₆C,  (SEQ ID NO: 76) CX₁₀CX₃CX₃CX₅CX₇CXCX₆C,(SEQ ID NO: 77) CX₁₀CX₄CX₅CX₁₂CX₂C,  (SEQ ID NO: 78)CX₁₂CX₄CX₅CXCXCX₉CX₃C,  (SEQ ID NO: 79) CX₁₂CX₄CX₅CX₁₂CX₂C, (SEQ ID NO: 80) CX₁₉CX₆CX₅CXCX₁₁C,  (SEQ ID NO: 81) CX₁₆CX₅CXCXCX₁₄C, (SEQ ID NO: 82) CX₁₀CX₅CXCX₈CX₆C, (SEQ ID NO: 83) CX₁₂CX₄CX₅CX₈CX₂C, (SEQ ID NO: 84) CX₁₂CX₅CX₅CXCX₈C, (SEQ ID NO: 85)CX₁₀CX₆CX₅CXCX₄CXCX₉C,  (SEQ ID NO: 86) CX₁₁CX₄CX₅CX₈CX₂C, (SEQ ID NO: 87) CX₁₉CX₆CX₅CX₈CX₂C,  (SEQ ID NO: 88) CX₁₉CX₆CX₅CXCX₈C,(SEQ ID NO: 89) CX₁₀CX₆CX₅CXCX₃CX₈CX₂C,  (SEQ ID NO: 90)CX₁₉CX₆CX₅CX₃CX₈C,  (SEQ ID NO: 91) CX₁₉CX₆CX₅CXCX₂CX₆CX₅C, (SEQ ID NO: 92) CX₇CX₆CX₃CX₃CX₉C,  (SEQ ID NO: 93) CX₉CX₈CX₅CX₆CX₅C, (SEQ ID NO: 94) CX₁₉CX₂CX₂CX₇CXCX₁₁CX₅C,  and  (SEQ ID NO: 95)CX₁₉CX₆CX₅CXCX₂CX₈CX₄C.


78. The library of claim 76, wherein the cysteine motif is selected fromthe group consisting of: (SEQ ID NO: 96) CCX₃CXCX₃CX₂CCXCX₅CX₉CX₅CXC,  (SEQ ID NO: 97) CX₆CX₂CX₅CX₄CCXCX₄CX₆CXC,  (SEQ ID NO: 98)CX₇CXCX₅CX₄CCCX₄CX₆CXC,  (SEQ ID NO: 99) CX₉CX₃CXCX₂CXCCCX₆CX₄C,(SEQ ID NO: 100) CX₅CX₃CXCX₄CX₄CCX₁₀CX₂CC, (SEQ ID NO: 101)CX₅CXCX₁CXCX₃CCX₃CX₄CX₁₀C,  (SEQ ID NO: 102) CX₉CCCX₃CX₄CCCX₅CX₆C, (SEQ ID NO: 103) CCX₈CX₅CX₄CX₃CX₄CCXCX₁C, (SEQ ID NO: 104)CCX₆CCX₅CCCX₄CX₄CX₁₂C,  (SEQ ID NO: 105) CX₆CX₂CX₃CCCX₄CX₅CX₃CX₃C, (SEQ ID NO: 106) CX₃CX₅CX₆CX₄CCXCX₅CX₄CXC, (SEQ ID NO: 107)CX₄CX₄CCX₄CX₄CXCX₁₁CX₂CXC,  (SEQ ID NO: 108) CX₅CX₂CCX₅CX₄CCX₃CCX₇C, (SEQ ID NO: 109) CX₅CX₅CX₃CX₂CXCCX₄CX₇CXC, (SEQ ID NO: 110)CX₃CX₇CX₃CX₄CCXCX₂CX₅CX₂C,  (SEQ ID NO: 111) CX₉CX₃CXCX₄CCX₅CCCX₆C, (SEQ ID NO: 112) CX₉CX₃CXCX₂CXCCX₆CX₃CX₃C, (SEQ ID NO: 113)CX₈CCXCX₃CCX₃CXCX₃CX₄C,  (SEQ ID NO: 114) CX₉CCX₄CX₂CXCCXCX₄CX₃C, (SEQ ID NO: 115) CX₁₀CXCX₃CX₂CXCCX₄CX₅CXC, (SEQ ID NO: 116)CX₉CXCX₃CX₂CXCCX₄CX₅CXC,  (SEQ ID NO: 117) CX₆CCXCX₅CX₄CCXCX₅CX₂C,(SEQ ID NO: 118) CX₆CCXCX₃CXCCX₃CX₄CC, (SEQ ID NO: 119)CX₆CCXCX₃CXCX₂CXCX₄CX₈C,  (SEQ ID NO: 120) CX₄CX₂CCX₃CXCX₄CCX₂CX₃C,(SEQ ID NO: 121) CX₃CX₅CX₃CCCX₄CX₉C, (SEQ ID NO: 122)CCX₉CX₃CXCCX₃CX₅C,  (SEQ ID NO: 123) CX₉CX₂CX₃CX₄CCX₄CX₅C, (SEQ ID NO: 124) CX₉CX₇CX₄CCXCX₇CX₃C,  (SEQ ID NO: 125)CX₉CX₃CCCX₁₀CX₂CX₃C, (SEQ ID NO: 126) CX₃CX₅CX₅CX₄CCX₁₀CX₆C,(SEQ ID NO: 127) CX₉CX₅CX₄CCXCX₅CX₄C,  (SEQ ID NO: 128)CX₇CXCX₆CX₄CCCX₁₀C,  (SEQ ID NO: 129) CX₉CX₂CX₄CCX₄CX₃CX₃C, (SEQ ID NO: 130) CX₇CX₅CXCX₄CCX₇CX₄C,  (SEQ ID NO: 131)CX₁₁CX₃CX₄CCCX₉CX₂C, (SEQ ID NO: 132) CX₂CX₃CX₄CCX₄CX₅CX₁₅C, (SEQ ID NO: 133) CX₉CX₅CX₄CCX₇C,  (SEQ ID NO: 134) CX₉CX₇CX₃CX₂CX₆C, (SEQ ID NO: 135) CX₉CX₅CX₄CCX₁₄C,  (SEQ ID NO: 136) CX₉CX₅CX₄CCX₉C, (SEQ ID NO: 137) CX₉CX₆CX₄CCXC, (SEQ ID NO: 138) CX₅CCX₇CX₄CX₁₂, (SEQ ID NO: 139) CX₁₀CX₃CX₄CCX₄C, (SEQ ID NO: 140) CX₉CX₄CCX₅CX₄C, (SEQ ID NO: 141) CX₁₀CX₃CX₄CX₇CXC, (SEQ ID NO: 142) CX₇CX₇CX₂CX₂CX₃C, (SEQ ID NO: 143) CX₉CX₄CX₄CCX₆C, (SEQ ID NO: 144) CX₇CXCX₃CXCX₆C, (SEQ ID NO: 145) CX₇CXCX₄CXCX₄C, (SEQ ID NO: 146) CX₉CX₅CX₄C, (SEQ ID NO: 147) CX₃CX₆CX₉C,  (SEQ ID NO: 148) CX₁₀CXCX₄C, (SEQ ID NO: 149) CX₁₀CCX₄C,  (SEQ ID NO: 150) CX₁₅C,  (SEQ ID NO: 151)CX₁₀C,  and  (SEQ ID NO: 152) CX₉C.


79. The library of claim 71, wherein the ultralong CDR3 comprises 2 to 6disulfide bonds.
 80. The library of claim 71, wherein the ultralong CDR3comprises SEQ ID NO: 40 or a derivative thereof.
 81. The library ofclaim 71, wherein the ultralong CDR3 comprises amino acid residues 3-6of any of one SEQ ID NO: 1-4.
 82. The library of claim 71, wherein theultralong CDR3 comprises a non-human DH or a derivative thereof.
 83. Thelibrary of claim 82, wherein the non-human DH is SEQ ID NO: 5, SEQ IDNO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ IDNO: 11, or SEQ ID NO: 12
 84. The library of claim 71, wherein theultralong CDR3 comprises a JH sequence or a derivative thereof.
 85. Thelibrary of claim 84, wherein the JH sequence is SEQ ID NO: 13, SEQ IDNO: 14, SEQ ID NO: 15, SEQ ID NO: 16, or SEQ ID NO:
 17. 86. The libraryof claim 71, wherein the ultralong CDR3 comprises: a non-human VHsequence or a derivative thereof; a non-human DH sequence or aderivative thereof; and/or a JH sequence or derivative thereof.
 87. Thelibrary of claim 86, wherein the ultralong CDR3 comprises an additionalamino acid sequence comprising two to six amino acid residues or morepositioned between the VH sequence and the DH sequence.
 88. The libraryof claim 87, wherein the additional amino acid sequence is selected fromthe group consisting of: IR, IF, SEQ ID NO: 18, SEQ ID NO: 19, SEQ IDNO: 20 or SEQ ID NO:
 21. 89. The library of claim 71, wherein theultralong CDR3 comprises a sequence derived from or based on SEQ ID NO:22, SEQ ID NO: 23, SEQ ID NO: 24, SEQ ID NO: 25, SEQ ID NO: 26, SEQ IDNO: 27, or SEQ ID NO:
 28. 90. The library of claim 71, wherein theultralong CDR3 comprises a non-bovine sequence or a non-antibodysequence.
 91. The library of claim 90, wherein the non-antibody sequenceis a synthetic sequence.
 92. The library of claim 90, wherein thenon-antibody sequence is a cytokine sequence, a lymphokine sequence, achemokine sequence, a growth factor sequence, a hormone sequence, or atoxin sequence.
 93. The library of claim 90, wherein the non-antibodysequence is an IL-8 sequence, an IL-21 sequence, an SDF-1 (alpha)sequence, a somatostatin sequence, a chlorotoxin sequence, a Pro-TxIIsequence, or a ziconotide sequence.
 94. The library of claim 90, whereinthe non-antibody sequence is any one of SEQ ID NOS: 475-481.
 95. Thelibrary of claim 71, wherein the ultralong CDR3 comprises a X¹X²X³X⁴X⁵motif, wherein X¹ is threonine (T), glycine (G), alanine (A), serine(S), or valine (V), wherein X² is serine (S), threonine (T), proline(P), isoleucine (I), alanine (A), valine (V), or asparagine (N), whereinX³ is valine (V), alanine (A), threonine (T), or aspartic acid (D),wherein X⁴ is histidine (H), threonine (T), arginine (R), tyrosine (Y),phenylalanine (F), or leucine (L), and wherein X⁵ is glutamine (Q). 96.The library of claim 95, wherein the X¹X²X³X⁴X⁵ motif is TTVHQ (SEQ IDNO: 153), TSVHQ (SEQ ID NO: 154), SSVTQ (SEQ ID NO: 155), STVHQ (SEQ IDNO: 156), ATVRQ (SEQ ID NO: 157), TTVYQ (SEQ ID NO: 158), SPVHQ (SEQ IDNO: 159), ATVYQ (SEQ ID NO: 160), TAVYQ (SEQ ID NO: 161), TNVHQ (SEQ IDNO: 162), ATVHQ (SEQ ID NO: 163), STVYQ (SEQ ID NO: 164), TIVHQ (SEQ IDNO: 165), AIVYQ (SEQ ID NO: 166), TTVFQ (SEQ ID NO: 167), AAVFQ (SEQ IDNO: 168), GTVHQ (SEQ ID NO: 169), ASVHQ (SEQ ID NO: 170), TAVFQ (SEQ IDNO: 171), ATVFQ (SEQ ID NO: 172), AAAHQ (SEQ ID NO: 173), VVVYQ (SEQ IDNO: 174), GTVFQ (SEQ ID NO: 175), TAVHQ (SEQ ID NO: 176), ITVHQ (SEQ IDNO: 177), ITAHQ (SEQ ID NO: 178), VTVHQ (SEQ ID NO: 179); AAVHQ (SEQ IDNO: 180), GTVYQ (SEQ ID NO: 181), TTVLQ (SEQ ID NO: 182), TTTHQ (SEQ IDNO: 183), or TTDYQ (SEQ ID NO: 184).
 97. The library of claim 71,wherein the ultralong CDR3 comprises a CX¹X²X³X⁴X⁵ motif.
 98. Thelibrary of claim 97, wherein the CX¹X²X³X⁴X⁵ motif is CTTVHQ (SEQ ID NO:185), CTSVHQ (SEQ ID NO: 186), CSSVTQ (SEQ ID NO: 187), CSTVHQ (SEQ IDNO: 188), CATVRQ (SEQ ID NO: 189), CTTVYQ (SEQ ID NO: 190), CSPVHQ (SEQID NO: 191), CATVYQ (SEQ ID NO: 192), CTAVYQ (SEQ ID NO: 193), CTNVHQ(SEQ ID NO: 194), CATVHQ (SEQ ID NO: 195), CSTVYQ (SEQ ID NO: 196),CTIVHQ (SEQ ID NO: 197), CAIVYQ (SEQ ID NO: 198), CTTVFQ (SEQ ID NO:199), CAAVFQ (SEQ ID NO: 200), CGTVHQ (SEQ ID NO: 201), CASVHQ (SEQ IDNO: 202), CTAVFQ (SEQ ID NO: 203), CATVFQ (SEQ ID NO: 204), CAAAHQ (SEQID NO: 205), CVVVYQ (SEQ ID NO: 206), CGTVFQ (SEQ ID NO: 207), CTAVHQ(SEQ ID NO: 208), CITVHQ (SEQ ID NO: 209), CITAHQ (SEQ ID NO: 210),CVTVHQ (SEQ ID NO: 211); CAAVHQ (SEQ ID NO: 212), CGTVYQ (SEQ ID NO:213), CTTVLQ (SEQ ID NO: 214), CTTTHQ (SEQ ID NO: 215), or CTTDYQ (SEQID NO: 216).
 99. The library of claim 71, wherein the ultralong CDR3comprises a (X^(a)X^(b))_(z) motif, wherein X^(a) is any amino acidresidue, X^(b) is an aromatic amino acid selected from the groupconsisting of: tyrosine (Y), phenylalanine (F), tryptophan (W), andhistidine (H), and wherein z is 1-4.
 100. The library of claim 99,wherein the (X^(a)X^(b))_(z) motif is CYTYNYEF (SEQ ID NO: 217),HYTYTYDF (SEQ ID NO: 218), HYTYTYEW (SEQ ID NO: 219), KHRYTYEW (SEQ IDNO: 220), NYIYKYSF (SEQ ID NO: 221), PYIYTYQF (SEQ ID NO: 222), SFTYTYEW(SEQ ID NO: 223), SYIYIYQW (SEQ ID NO: 224), SYNYTYSW (SEQ ID NO: 225),SYSYSYEY (SEQ ID NO: 226), SYTYNYDF (SEQ ID NO: 227), SYTYNYEW (SEQ IDNO: 228), SYTYNYQF (SEQ ID NO: 229), SYVWTHNF (SEQ ID NO: 230), TYKYVYEW(SEQ ID NO: 231), TYTYTYEF (SEQ ID NO: 232), TYTYTYEW (SEQ ID NO: 233),VFTYTYEF (SEQ ID NO: 234), AYTYEW (SEQ ID NO: 235), DYIYTY (SEQ ID NO:236), IHSYEF (SEQ ID NO: 237), SFTYEF (SEQ ID NO: 238), SHSYEF (SEQ IDNO: 239), THTYEF (SEQ ID NO: 240), TWTYEF (SEQ ID NO: 241), TYNYEW (SEQID NO: 242), TYSYEF (SEQ ID NO: 243), TYSYEH (SEQ ID NO: 244), TYTYDF(SEQ ID NO: 245), TYTYEF (SEQ ID NO: 246), TYTYEW (SEQ ID NO: 247), AYEF(SEQ ID NO: 248), AYSF (SEQ ID NO: 249), AYSY (SEQ ID NO: 250), CYSF(SEQ ID NO: 251), DYTY (SEQ ID NO: 252), KYEH (SEQ ID NO: 253), KYEW(SEQ ID NO: 254), MYEF (SEQ ID NO: 255), NWIY (SEQ ID NO: 256), NYDY(SEQ ID NO: 257), NYQW (SEQ ID NO: 258), NYSF (SEQ ID NO: 259), PYEW(SEQ ID NO: 260), RYNW (SEQ ID NO: 261), RYTY (SEQ ID NO: 262), SYEF(SEQ ID NO: 263), SYEH (SEQ ID NO: 264), SYEW (SEQ ID NO: 265), SYKW(SEQ ID NO: 266), SYTY (SEQ ID NO: 267), TYDF (SEQ ID NO: 268), TYEF(SEQ ID NO: 269), TYEW (SEQ ID NO: 270), TYQW (SEQ ID NO: 271), TYTY(SEQ ID NO: 272), or VYEW (SEQ ID NO: 273).
 101. The library of claim99, wherein the (X^(a)X^(b)), motif is YXYXYX.
 102. The library of claim71, wherein the ultralong CDR3 comprises a X¹X²X³X⁴X⁵X_(n) motif,wherein X¹ is threonine (T), glycine (G), alanine (A), serine (S), orvaline (V), wherein X² is serine (S), threonine (T), proline (P),isoleucine (I), alanine (A), valine (V), or asparagine (N), wherein X³is valine (V), alanine (A), threonine (T), or aspartic acid (D), whereinX⁴ is histidine (H), threonine (T), arginine (R), tyrosine (Y),phenylalanine (F), or leucine (L), and wherein X⁵ is glutamine (Q), andwherein n is 27-54.
 103. The library of claim 71, wherein the ultralongCDR3 comprises X_(n)(X^(a)X^(b))_(z) motif, wherein X^(a) is any aminoacid residue, X^(b) is an aromatic amino acid selected from the groupconsisting of: tyrosine (Y), phenylalanine (F), tryptophan (W), andhistidine (H), wherein n is 27-54, and wherein z is 1-4.
 104. Thelibrary of claim 71, wherein the ultralong CDR3 comprises aX¹X²X³X⁴X⁵X_(n)(X^(a)X^(b))_(z) motif, wherein X₁ is threonine (T),glycine (G), alanine (A), serine (S), or valine (V), wherein X₂ isserine (S), threonine (T), proline (P), isoleucine (I), alanine (A),valine (V), or asparagine (N), wherein X₃ is valine (V), alanine (A),threonine (T), or aspartic acid (D), wherein X₄ is histidine (H),threonine (T), arginine (R), tyrosine (Y), phenylalanine (F), or leucine(L), wherein X₅ is glutamine (Q), X^(a) is any amino acid residue, X^(b)is an aromatic amino acid selected from the group consisting of:tyrosine (Y), phenylalanine (F), tryptophan (W), and histidine (H),wherein n is 27-54, and wherein z is 1-4.
 105. The library of claim 104,wherein the X¹X²X³X⁴X⁵ motif is TTVHQ (SEQ ID NO: 153) or TSVHQ (SEQ IDNO: 154), and wherein the (X^(a)X^(b))_(z) motif is YXYXYX.
 106. Thelibrary of claim 71, wherein the ultralong CDR3 comprises: a CX¹X²X³X⁴X⁵motif, wherein X¹ is threonine (T), glycine (G), alanine (A), serine(S), or valine (V), wherein X² is serine (S), threonine (T), proline(P), isoleucine (I), alanine (A), valine (V), or asparagine (N), whereinX³ is valine (V), alanine (A), threonine (T), or aspartic acid (D),wherein X⁴ is histidine (H), threonine (T), arginine (R), tyrosine (Y),phenylalanine (F), or leucine (L), and wherein X⁵ is glutamine (Q), acysteine motif selected from the group consisting of: CX₁₀CX₅CX₅CXCX₇C(SEQ ID NO: 41), CX₁₀CX₆CX₅CXCX₁₅C (SEQ ID NO: 42), CX₁₁CXCX₅C (SEQ IDNO: 43), CX₁₁CX₅CX₅CXCX₇C (SEQ ID NO: 44), CX₁₀CX₆CX₅CXCX₁₃C (SEQ ID NO:45), CX₁₀CX₅CXCX₄CX₈C (SEQ ID NO: 46), CX₁₀CX₆CX₆CXCX₇C (SEQ ID NO: 47),CX₁₀CX₄CX₇CXCX₈C (SEQ ID NO: 48), CX₁₀CX₄CX₇CXCX₇C (SEQ ID NO: 49),CX₁₃CX₈CX₈C (SEQ ID NO: 50), CX₁₀CX₆CX₅CXCX₇C (SEQ ID NO: 51),CX₁₀CX₅CX₅C (SEQ ID NO: 52), CX₁₀CX₅CX₆CXCX₇C (SEQ ID NO: 53),CX₁₀CX₆CX₅CX₇CX₉C (SEQ ID NO: 54), CX₉CX₇CX₅CXCX₇C (SEQ ID NO: 55),CX₁₀CX₆CX₅CXCX₉C (SEQ ID NO: 56), CX₁₀CXCX₄CX₅CX₁₁C (SEQ ID NO: 57),CX₇CX₃CX₆CX₅CXCX₅CX₁₀C (SEQ ID NO: 58), CX₁₀CXCX₄CX₅CXCX₂CX₃C (SEQ IDNO: 59), CX₁₆CX₅CXC (SEQ ID NO: 60), CX₆CX₄CXCX₄CX₅C (SEQ ID NO: 61),CX₁₁CX₄CX₅CX₆CX₃C (SEQ ID NO: 62), CX₈CX₂CX₆CX₅C (SEQ ID NO: 63),CX₁₀CX₅CX₅CXCX₁₀C (SEQ ID NO: 64), CX₁₀CXCX₆CX₄CXC (SEQ ID NO: 65),CX₁₀CX₅CX₅CXCX₂C (SEQ ID NO: 66), CX₁₄CX₂CX₃CXCXC (SEQ ID NO: 67),CX₁₅CX₅CXC (SEQ ID NO: 68), CX₄CX₆CX₉CX₂CX₁₁C (SEQ ID NO: 69),CX₆CX₄CX₅CX₅CX₁₂C (SEQ ID NO: 70), CX₇CX₃CXCXCX₄CX₅CX₉C (SEQ ID NO: 71),CX₁₀CX₆CX₅C (SEQ ID NO: 72), CX₇CX₃CX₅CX₅CX₉C (SEQ ID NO: 73),CX₇CX₅CXCX₂C (SEQ ID NO: 74), CX₁₀CXCX₆C (SEQ ID NO: 75),CX₁₀CX₃CX₃CX₅CX₇CXCX₆C (SEQ ID NO: 76), CX₁₀CX₄CX₅CX₁₂CX₂C (SEQ ID NO:77), CX₁₂CX₄CX₅CXCXCX₉CX₃C (SEQ ID NO: 78), CX₁₂CX₄CX₅CX₁₂CX₂C (SEQ IDNO: 79), CX₁₀CX₆CX₅CXCX₁₁C (SEQ ID NO: 80), CX₁₆CX₅CXCXCX₁₄C (SEQ ID NO:81), CX₁₀CX₅CXCX₈CX₆C (SEQ ID NO: 82), CX₁₂CX₄CX₅CX₈CX₂C (SEQ ID NO:83), CX₁₂CX₅CX₅CXCX₈C (SEQ ID NO: 84), CX₁₀CX₆CX₅CXCX₄CXCX₉C (SEQ ID NO:85), CX₁₁CX₄CX₅CX₈CX₂C (SEQ ID NO: 86), CX₁₀CX₆CX₅CX₈CX₂C (SEQ ID NO:87), CX₁₀CX₆CX₅CXCX₈C (SEQ ID NO: 88), CX₁₀CX₆CX₅CXCX₃CX₈CX₂C (SEQ IDNO: 89), CX₁₀CX₆CX₅CX₃CX₈C (SEQ ID NO: 90), CX₁₀CX₆CX₅CXCX₂CX₆CX₅C (SEQID NO: 91), CX₇CX₆CX₃CX₃CX₉C (SEQ ID NO: 92), CX₉CX₈CX₅CX₆CX₅C (SEQ IDNO: 93), CX₁₀CX₂CX₂CX₇CXCX₁₁CX₅C (SEQ ID NO: 94), andCX₁₀CX₆CX₅CXCX₂CX₈CX₄C (SEQ ID NO: 95), and a (X^(a)X^(b))_(z) motif,X^(a) is any amino acid residue, X^(b) is an aromatic amino acidselected from the group consisting of: tyrosine (Y), phenylalanine (F),tryptophan (W), and histidine (H), and wherein z is 1-4.
 107. Thelibrary of claim 71, wherein the ultralong CDR3 comprises: a CX¹X²X³X⁴X⁵motif, wherein X¹ is threonine (T), glycine (G), alanine (A), serine(S), or valine (V), wherein X² is serine (S), threonine (T), proline(P), isoleucine (I), alanine (A), valine (V), or asparagine (N), whereinX³ is valine (V), alanine (A), threonine (T), or aspartic acid (D),wherein X⁴ is histidine (H), threonine (T), arginine (R), tyrosine (Y),phenylalanine (F), or leucine (L), and wherein X⁵ is glutamine (Q); acysteine motif selected from the group consisting of: wherein thecysteine motif is selected from the group consisting of:CCX₃CXCX₃CX₂CCXCX₅CX₉CX₅CXC (SEQ ID NO: 96), CX₆CX₂CX₅CX₄CCXCX₄CX₆CXC(SEQ ID NO: 97), CX₇CXCX₅CX₄CCCX₄CX₆CXC (SEQ ID NO: 98),CX₉CX₃CXCX₂CXCCCX₆CX₄C (SEQ ID NO: 99), CX₅CX₃CXCX₄CX₄CCX₁₀CX₂CC (SEQ IDNO: 100), CX₅CXCX₁CXCX₃CCX₃CX₄CX₁₀C (SEQ ID NO: 101),CX₉CCCX₃CX₄CCCX₅CX₆C (SEQ ID NO: 102), CCX₈CX₅CX₄CX₃CX₄CCXCX₁C (SEQ IDNO: 103), CCX₆CCX₅CCCX₄CX₄CX₁₂C (SEQ ID NO: 104),CX₆CX₂CX₃CCCX₄CX₅CX₃CX₃C (SEQ ID NO: 105), CX₃CX₅CX₆CX₄CCXCX₅CX₄CXC (SEQID NO: 106), CX₄CX₄CCX₄CX₄CXCX₁₁CX₂CXC (SEQ ID NO: 107),CX₅CX₂CCX₅CX₄CCX₃CCX₇C (SEQ ID NO: 108), CX₅CX₅CX₃CX₂CXCCX₄CX₇CXC (SEQID NO: 109), CX₃CX₇CX₃CX₄CCXCX₂CX₅CX₂C (SEQ ID NO: 110),CX₉CX₃CXCX₄CCX₅CCCX₆C (SEQ ID NO: 111), CX₉CX₃CXCX₂CXCCX₆CX₃CX₃C (SEQ IDNO: 112), CX₈CCXCX₃CCX₃CXCX₃CX₄C (SEQ ID NO: 113),CX₉CCX₄CX₂CXCCXCX₄CX₃C (SEQ ID NO: 114), CX₁₀CXCX₃CX₂CXCCX₄CX₅CXC (SEQID NO: 115), CX₉CXCX₃CX₂CXCCX₄CX₅CXC (SEQ ID NO: 116),CX₆CCXCX₅CX₄CCXCX₅CX₂C (SEQ ID NO: 117), CX₆CCXCX₃CXCCX₃CX₄CC (SEQ IDNO: 118), CX₆CCXCX₃CXCX₂CXCX₄CX₈C (SEQ ID NO: 119),CX₄CX₂CCX₃CXCX₄CCX₂CX₃C (SEQ ID NO: 120), CX₃CX₅CX₃CCCX₄CX₉C (SEQ ID NO:121), CCX₉CX₃CXCCX₃CX₅C (SEQ ID NO: 122), CX₉CX₂CX₃CX₄CCX₄CX₅C (SEQ IDNO: 123), CX₉CX₇CX₄CCXCX₇CX₃C (SEQ ID NO: 124), CX₉CX₃CCCX₁₀CX₂CX₃C (SEQID NO: 125), CX₃CX₅CX₅CX₄CCX₁₀CX₆C (SEQ ID NO: 126), CX₉CX₅CX₄CCXCX₅CX₄C(SEQ ID NO: 127), CX₇CXCX₆CX₄CCCX₁₀C (SEQ ID NO: 128),CX₈CX₂CX₄CCX₄CX₃CX₃C (SEQ ID NO: 129), CX₇CX₅CXCX₄CCX₇CX₄C (SEQ ID NO:130), CX₁₁CX₃CX₄CCCX₈CX₂C (SEQ ID NO: 131), CX₂CX₃CX₄CCX₄CX₅CX₁₅C (SEQID NO: 132), CX₉CX₅CX₄CCX₇C (SEQ ID NO: 133), CX₉CX₇CX₃CX₂CX₆C (SEQ IDNO: 134), CX₉CX₅CX₄CCX₁₄C (SEQ ID NO: 135), CX₉CX₅CX₄CCX₈C (SEQ ID NO:136), CX₉CX₆CX₄CCXC (SEQ ID NO: 137), CX₅CCX₇CX₄CX₁₂ (SEQ ID NO: 138),CX₁₀CX₃CX₄CCX₄C (SEQ ID NO: 139), CX₉CX₄CCX₅CX₄C (SEQ ID NO: 140),CX₁₀CX₃CX₄CX₇CXC (SEQ ID NO: 141), CX₇CX₇CX₂CX₂CX₃C (SEQ ID NO: 142),CX₉CX₄CX₄CCX₆C (SEQ ID NO: 143), CX₇CXCX₃CXCX₆C (SEQ ID NO: 144),CX₇CXCX₄CXCX₄C (SEQ ID NO: 145), CX₉CX₅CX₄C (SEQ ID NO: 146), CX₃CX₆CX₈C(SEQ ID NO: 147), CX₁₀CXCX₄C (SEQ ID NO: 148), CX₁₀CCX₄C (SEQ ID NO:149), CX₁₅C (SEQ ID NO: 150), CX₁₀C (SEQ ID NO: 151), and CX₉C (SEQ IDNO: 152); and a (X^(a)X^(b))_(z) motif, wherein X^(a) is any amino acidresidue, X^(b) is an aromatic amino acid selected from the groupconsisting of: tyrosine (Y), phenylalanine (F), tryptophan (W), andhistidine (H), and wherein z is 1-4.
 108. The library of claim 90,wherein the ultralong CDR3 comprises an additional sequence that is alinker.
 109. The library of claim 108, wherein the linker is linked to aC-terminus, a N-terminus, or both C-terminus and N-terminus of thenon-antibody sequence.
 110. The library of claim 71, wherein theultralong CDR3 is a ruminant CDR3.
 111. The library of claim 110,wherein the ruminant is a cow.
 112. The library of claim 71, wherein thehumanized antibody or binding fragment thereof comprises a human heavychain germline sequence that is a VH4 family member germline sequence.113. The library of claim 71, wherein the humanized antibody or bindingfragment thereof comprises a VH4-34 germline sequence.
 114. The libraryof claim 71, wherein the humanized antibody or binding fragment thereofcomprises a human heavy chain germline sequence that is derived fromVH4-34.
 115. The library of claim 114, wherein the VH4-34 germlinesequence comprises a CDR1 comprising a Gly31Asp and Tyr32Lyssubstitution based on Kabat numbering.
 116. The library of claim 114,wherein the VH4-34 germline sequence comprises a CDR2 comprising aGlu50Ser substitution based on Kabat numbering.
 117. The library ofclaim 114, wherein the VH4-34 germline sequence comprises a CDR1comprising Ala23Thr, Val24Ala, Tyr25Ser, Gly27Phe, Phe29Leu, Gly31Asp,Tyr32Lys, Tyr33Ala, Trp34Val, and Ser35Gly substitutions, and a CDR2comprising Ile48Leu, Glu50Ser, Asn52Asp, His53Thr, Ser54Gly, Ser56Asn,and Asn58Gly substitutions, based on Kabat numbering.
 118. The libraryof claim 71, wherein the humanized antibody or binding fragment thereofcomprises the amino acid sequence set forth in SEQ ID NO:
 470. 119. Thelibrary of claim 71, wherein the humanized antibody or binding fragmentthereof comprises the amino acid sequence set forth in SEQ ID NO: 461,462, 463, 464, 465, 466, 467, 468, or 469; and the amino acid sequenceset forth in SEQ ID NO:
 470. 120. The library of claim 71, wherein thehumanized antibody or binding fragment thereof comprises the amino acidsequence set forth in SEQ ID NO: 461, 462, 463, 464, 465, 466, 467, 468,or 469; the amino acid sequence set forth in SEQ ID NO: 470; and apeptide sequence, wherein the peptide sequence is positioned between SEQID NO: 461, 462, 463, 464, 465, 466, 467, 468, or 4697, and SEQ ID NO:470.
 121. The library of claim 120, wherein the peptide sequence is abovine sequence, a non-bovine sequence, an antibody sequence, or anon-antibody sequence.
 122. The library of claim 71, wherein thehumanized antibody or binding fragment thereof comprises a light chainvariable region sequence that is a lambda light chain variable regionsequence.
 123. The library of claim 122, wherein the lambda light chainvariable region sequence is a bovine lambda light chain variable regionsequence.
 124. The library of claim 122, wherein the lambda light chainvariable region sequence is a human lambda light chain variable regionsequence.
 125. The library of claim 124, wherein the human lambda lightchain variable region sequence is VL1-51.
 126. The library of claim 124,wherein the human lambda light chain variable region sequence is derivedfrom VL1-51.
 127. The library of claim 126, wherein the VL1-51 germlinesequence comprises a CDR1 comprising Ile29Val and Asn32Gly substitutionbased on Kabat numbering.
 128. The library of claim 126, wherein theVL1-51 germline sequence comprises a CDR2 comprising a substitution ofDNN to GDT.
 129. The library of claim 126, wherein the VL1-51 germlinesequence comprises a CDR2 comprising a substitution of DNNKRP (SEQ IDNO: 471) to GDTSRA (SEQ ID NO: 472).
 130. The library of claim 126,wherein the VL1-51 germline sequence comprises a S2A, T5N, P8S, A12G,A13S, and P14L substitution based on Kabat numbering.
 131. The libraryof claim 126, wherein the VL1-51 germline sequence comprises a S2A, T5N,P8S, A12G, A13S, and P14L substitution based on Kabat numbering, and aCDR2 comprising a substitution of DNN to GDT.
 132. The library of claim71, wherein the humanized antibody or binding fragment thereofcomprising the amino acid sequence set forth in SEQ ID NO: 440, 441,442, 443, or
 444. 133. The library of any one of claims 71-132, whereinthe humanized antibodies or binding fragments thereof are present in aspatially addressed format.
 134. A method of humanizing an antibodyvariable region comprising the step of genetically combining a nucleicacid sequence encoding a non-human ultralong CDR3 with a nucleic acidsequence encoding a human variable region framework (FR) sequence. 135.A method of generating a library of humanized antibodies that comprisesan ultralong CDR3, the method comprising: a.) combining a nucleic acidsequence encoding an ultralong CDR3 with a nucleic acid sequenceencoding a human variable region framework (FR) sequence to producenucleic acids encoding for humanized antibodies that comprises anultralong CDR3; and b.) expressing the nucleic acids encoding forhumanized antibodies that comprises an ultralong CDR3 to generate alibrary of humanized antibodies that comprises an ultralong CDR3.
 136. Amethod of generating a library of humanized antibodies or bindingfragments thereof comprising an ultralong CDR3 that comprises anon-antibody sequence, the method comprising: a.) combining a nucleicacid sequence encoding an ultralong CDR3, a nucleic acid sequenceencoding a human variable region framework (FR) sequence, and a nucleicacid sequence encoding a non-antibody sequence to produce nucleic acidsencoding humanized antibodies or binding fragments thereof comprising anultralong CDR3 and a non-antibody sequence, and b.) expressing thenucleic acids encoding humanized antibodies or binding fragments thereofcomprising an ultralong CDR3 and a non-antibody sequence to generate alibrary of humanized antibodies or binding fragments thereof comprisingan ultralong CDR3 and a non-antibody sequence.
 137. A library ofhumanized antibodies or binding fragments thereof comprising anultralong CDR3 that comprises a non-antibody sequence.
 138. A method ofgenerating a library of humanized antibodies or binding fragmentsthereof comprising an ultralong CDR3 that comprises a cysteine motif,the method comprising: a.) combining a human variable region framework(FR) sequence, and a nucleic acid sequence encoding an ultralong CDR3and a cysteine motif; b.) introducing one or more nucleotide changes tothe nucleic acid sequence encoding one or more amino acid residues thatare positioned between one or more cysteine residues in the cysteinemotif for nucleotides encoding different amino acid residues to producenucleic acids encoding humanized antibodies or binding fragments thereofcomprising an ultralong CDR3 and a cysteine motif with one or morenucleotide changes introduced between one or more cysteine residues inthe cysteine domain; and c.) expressing the nucleic acids encodinghumanized antibodies or binding fragments thereof comprising anultralong CDR3 and a cysteine motif with one or more nucleotide changesintroduced between one or more cysteine residues in the cysteine domainto generate a library of humanized antibodies or binding fragmentsthereof comprising an ultralong CDR3 and a cysteine motif with one ormore amino acid changes introduced between one or more cysteine residuesin the cysteine domain.
 139. A library of humanized antibodies orbinding fragments thereof comprising an ultralong CDR3 that comprises acysteine motif, wherein the antibodies or binding fragments comprise oneor more substitutions of amino acid residues that are positioned betweencysteine residues in the cysteine motif.
 140. A method of generating alibrary of humanized antibodies or binding fragments thereof comprisinga bovine ultralong CDR3, the method comprising: a.) combining a nucleicacid sequence encoding a human variable region framework (FR) sequenceand a nucleic acid encoding a bovine ultralong CDR3, and b.) expressingthe nucleic acids encoding a human variable region framework (FR)sequence and a nucleic acid encoding a bovine ultralong CDR3 to generatea library of humanized antibodies or binding fragments thereofcomprising a bovine ultralong CDR3.
 141. A library of humanizedantibodies or binding fragments thereof comprising a bovine ultralongCDR3.
 142. A CDR3 scaffold comprising a X¹X²X³X⁴X⁵ motif, wherein X¹ isthreonine (T), glycine (G), alanine (A), serine (S), or valine (V),wherein X² is serine (S), threonine (T), proline (P), isoleucine (I),alanine (A), valine (V), or asparagine (N), wherein X³ is valine (V),alanine (A), threonine (T), or aspartic acid (D), wherein X⁴ ishistidine (H), threonine (T), arginine (R), tyrosine (Y), phenylalanine(F), or leucine (L), and wherein X⁵ is glutamine (Q).
 143. The CDR3scaffold of claim 142, wherein the CDR3 scaffold is 35 amino acids inlength or longer, 40 amino acids in length or longer, 45 amino acids inlength or longer, 50 amino acids in length or longer, 55 amino acids inlength or longer, or 60 amino acids in length or longer.
 144. The CDR3scaffold of claim 143, wherein the CDR3 scaffold is 35 amino acids inlength or longer.
 145. The CDR3 scaffold of claim 142, wherein the CDR3scaffold comprises 3 or more cysteine residues, 4 or more cysteineresidues, 5 or more cysteine residues, 6 or more cysteine residues, 7 ormore cysteine residues, 8 or more cysteine residues, 9 or more cysteineresidues, 10 or more cysteine residues, 11 or more cysteine residues, or12 or more cysteine residues.
 146. The CDR3 scaffold of claim 145,wherein the CDR3 scaffold comprises 3 or more cysteine residues. 147.The CDR3 scaffold of claim 142, wherein the CDR3 scaffold comprises acysteine motif.
 148. The CDR3 scaffold of claim 147, wherein thecysteine motif is selected from the group consisting of: (SEQ ID NO: 41)CX₁₀CX₅CX₅CXCX₇C,  (SEQ ID NO: 42) CX₁₀CX₆CX₅CXCX₁₅C,  (SEQ ID NO: 43)CX₁₁CXCX₅C,  (SEQ ID NO: 44) CX₁₁CX₅CX₅CXCX₇C,  (SEQ ID NO: 45)CX₁₀CX₆CX₅CXCX₁₃C,  (SEQ ID NO: 46) CX₁₀CX₅CXCX₄CX₈C, (SEQ ID NO: 47)CX₁₀CX₆CX₆CXCX₇C,  (SEQ ID NO: 48) CX₁₉CX₄CX₇CXCX₈C, (SEQ ID NO: 49)CX₁₀CX₄CX₇CXCX₇C,  (SEQ ID NO: 50) CX₁₃CX₈CX₈C, (SEQ ID NO: 51)CX₁₀CX₆CX₅CXCX₇C,  (SEQ ID NO: 52) CX₁₀CX₅CX₅C, (SEQ ID NO: 53)CX₁₀CX₅CX₆CXCX₇C,  (SEQ ID NO: 54) CX₁₉CX₆CX₅CX₇CX₉C, (SEQ ID NO: 55)CX₉CX₇CX₅CXCX₇C,  (SEQ ID NO: 56) CX₁₉CX₆CX₅CXCX₉C, (SEQ ID NO: 57)CX₁₀CXCX₄CX₅CX₁₁C,  (SEQ ID NO: 58) CX₇CX₃CX₆CX₅CXCX₅CX₁₉C,(SEQ ID NO: 59) CX₁₀CXCX₄CX₅CXCX₂CX₃C,  (SEQ ID NO: 60) CX₁₆CX₅CXC,(SEQ ID NO: 61) CX₆CX₄CXCX₄CX₅C, (SEQ ID NO: 62) CX₁₁CX₄CX₅CX₆CX₃C,(SEQ ID NO: 63) CX₈CX₂CX₆CX₅C,  (SEQ ID NO: 64) CX₁₀CX₅CX₅CXCX₁₀C,(SEQ ID NO: 65) CX₁₀CXCX₆CX₄CXC,  (SEQ ID NO: 66) CX₁₀CX₅CX₅CXCX₂C,(SEQ ID NO: 67) CX₁₄CX₂CX₃CXCXC,  (SEQ ID NO: 68) CX₁₅CX₅CXC,(SEQ ID NO: 69) CX₄CX₆CX₉CX₂CX₁₁C,  (SEQ ID NO: 70) CX₆CX₄CX₅CX₅CX₁₂C,(SEQ ID NO: 71) CX₇CX₃CXCXCX₄CX₅CX₉C,  (SEQ ID NO: 72) CX₁₀CX₆CX₅C,(SEQ ID NO: 73) CX₇CX₃CX₅CX₅CX₉C,  (SEQ ID NO: 74) CX₇CX₅CXCX₂C,(SEQ ID NO: 75) CX₁₀CXCX₆C,  (SEQ ID NO: 76) CX₁₀CX₃CX₃CX₅CX₇CXCX₆C,(SEQ ID NO: 77) CX₁₀CX₄CX₅CX₁₂CX₂C,  (SEQ ID NO: 78)CX₁₂CX₄CX₅CXCXCX₉CX₃C,  (SEQ ID NO: 79) CX₁₂CX₄CX₅CX₁₂CX₂C, (SEQ ID NO: 80) CX₁₀CX₆CX₅CXCX₁₁C,  (SEQ ID NO: 81) CX₁₆CX₅CXCXCX₁₄C, (SEQ ID NO: 82) CX₁₀CX₅CXCX₈CX₆C, (SEQ ID NO: 83) CX₁₂CX₄CX₅CX₈CX₂C, (SEQ ID NO: 84) CX₁₂CX₅CX₅CXCX₈C, (SEQ ID NO: 85)CX₁₀CX₆CX₅CXCX₄CXCX₉C,  (SEQ ID NO: 86) CX₁₁CX₄CX₅CX₈CX₂C, (SEQ ID NO: 87) CX₁₉CX₆CX₅CX₈CX₂C,  (SEQ ID NO: 88) CX₁₉CX₆CX₅CXCX₈C,(SEQ ID NO: 89) CX₁₀CX₆CX₅CXCX₃CX₈CX₂C,  (SEQ ID NO: 90)CX₁₉CX₆CX₅CX₃CX₈C,  (SEQ ID NO: 91) CX₁₉CX₆CX₅CXCX₂CX₆CX₅C, (SEQ ID NO: 92) CX₇CX₆CX₃CX₃CX₉C,  (SEQ ID NO: 93) CX₉CX₈CX₅CX₆CX₅C, (SEQ ID NO: 94) CX₁₉CX₂CX₂CX₇CXCX₁₁CX₅C,  and  (SEQ ID NO: 95)CX₁₉CX₆CX₅CXCX₂CX₈CX₄C.


149. The CDR3 scaffold of claim 147, wherein the cysteine motif isselected from the group consisting of: (SEQ ID NO: 96)CCX₃CXCX₃CX₂CCXCX₅CX₉CX₅CXC, (SEQ ID NO: 97) CX₆CX₂CX₅CX₄CCXCX₄CX₆CXC, (SEQ ID NO: 98) CX₇CXCX₅CX₄CCCX₄CX₆CXC,  (SEQ ID NO: 99)CX₉CX₃CXCX₂CXCCCX₆CX₄C, (SEQ ID NO: 100) CX₅CX₃CXCX₄CX₄CCX₁₀CX₂CC,(SEQ ID NO: 101) CX₅CXCX₁CXCX₃CCX₃CX₄CX₁₀C,  (SEQ ID NO: 102)CX₉CCCX₃CX₄CCCX₅CX₆C,  (SEQ ID NO: 103) CCX₈CX₅CX₄CX₃CX₄CCXCX₁C,(SEQ ID NO: 104) CCX₆CCX₅CCCX₄CX₄CX₁₂C,  (SEQ ID NO: 105)CX₆CX₂CX₃CCCX₄CX₅CX₃CX₃C,  (SEQ ID NO: 106) CX₃CX₅CX₆CX₄CCXCX₅CX₄CXC,(SEQ ID NO: 107) CX₄CX₄CCX₄CX₄CXCX₁₁CX₂CXC,  (SEQ ID NO: 108)CX₅CX₂CCX₅CX₄CCX₃CCX₇C,  (SEQ ID NO: 109) CX₅CX₅CX₃CX₂CXCCX₄CX₇CXC,(SEQ ID NO: 110) CX₃CX₇CX₃CX₄CCXCX₂CX₅CX₂C,  (SEQ ID NO: 111)CX₉CX₃CXCX₄CCX₅CCCX₆C,  (SEQ ID NO: 112) CX₉CX₃CXCX₂CXCCX₆CX₃CX₃C,(SEQ ID NO: 113) CX₈CCXCX₃CCX₃CXCX₃CX₄C,  (SEQ ID NO: 114)CX₉CCX₄CX₂CXCCXCX₄CX₃C,  (SEQ ID NO: 115) CX₁₀CXCX₃CX₂CXCCX₄CX₅CXC,(SEQ ID NO: 116) CX₉CXCX₃CX₂CXCCX₄CX₅CXC,  (SEQ ID NO: 117)CX₆CCXCX₅CX₄CCXCX₅CX₂C,  (SEQ ID NO: 118) CX₆CCXCX₃CXCCX₃CX₄CC,(SEQ ID NO: 119) CX₆CCXCX₃CXCX₂CXCX₄CX₈C,  (SEQ ID NO: 120)CX₄CX₂CCX₃CXCX₄CCX₂CX₃C, (SEQ ID NO: 121) CX₃CX₅CX₃CCCX₄CX₉C,(SEQ ID NO: 122) CCX₉CX₃CXCCX₃CX₅C,  (SEQ ID NO: 123)CX₉CX₂CX₃CX₄CCX₄CX₅C,  (SEQ ID NO: 124) CX₉CX₇CX₄CCXCX₇CX₃C, (SEQ ID NO: 125) CX₉CX₃CCCX₁₀CX₂CX₃C, (SEQ ID NO: 126)CX₃CX₅CX₅CX₄CCX₁₀CX₆C, (SEQ ID NO: 127) CX₉CX₅CX₄CCXCX₅CX₄C, (SEQ ID NO: 128) CX₇CXCX₆CX₄CCCX₁₀C,  (SEQ ID NO: 129)CX₈CX₂CX₄CCX₄CX₃CX₃C,  (SEQ ID NO: 130) CX₇CX₅CXCX₄CCX₇CX₄C,(SEQ ID NO: 131) CX₁₁CX₃CX₄CCCX₈CX₂C, (SEQ ID NO: 132)CX₂CX₃CX₄CCX₄CX₅CX₁₅C,  (SEQ ID NO: 133) CX₉CX₅CX₄CCX₇C, (SEQ ID NO: 134) CX₉CX₇CX₃CX₂CX₆C,  (SEQ ID NO: 135) CX₉CX₅CX₄CCX₁₄C, (SEQ ID NO: 136) CX₉CX₅CX₄CCX₈C,  (SEQ ID NO: 137) CX₉CX₆CX₄CCXC,(SEQ ID NO: 138) CX₅CCX₇CX₄CX₁₂,  (SEQ ID NO: 139) CX₁₀CX₃CX₄CCX₄C,(SEQ ID NO: 140) CX₉CX₄CCX₅CX₄C,  (SEQ ID NO: 141) CX₁₀CX₃CX₄CX₇CXC,(SEQ ID NO: 142) CX₇CX₇CX₂CX₂CX₃C,  (SEQ ID NO: 143) CX₉CX₄CX₄CCX₆C,(SEQ ID NO: 144) CX₇CXCX₃CXCX₆C,  (SEQ ID NO: 145) CX₇CXCX₄CXCX₄C,(SEQ ID NO: 146) CX₉CX₅CX₄C,  (SEQ ID NO: 147) CX₃CX₆CX₈C, (SEQ ID NO: 148) CX₁₀CXCX₄C,  (SEQ ID NO: 149) CX₁₀CCX₄C, (SEQ ID NO: 150) CX₁₅C,  (SEQ ID NO: 151) CX₁₀C,  and  (SEQ ID NO: 152)CX₉C.


150. The CDR3 scaffold of claim 142, wherein CDR3 scaffold comprises 2to 6 disulfide bonds.
 151. The CDR3 scaffold of claim 142, wherein theX¹X²X³X⁴X⁵ motif in the CDR3 scaffold is TTVHQ (SEQ ID NO: 153), TSVHQ(SEQ ID NO: 154), SSVTQ (SEQ ID NO: 155), STVHQ (SEQ ID NO: 156), ATVRQ(SEQ ID NO: 157), TTVYQ (SEQ ID NO: 158), SPVHQ (SEQ ID NO: 159), ATVYQ(SEQ ID NO: 160), TAVYQ (SEQ ID NO: 161), TNVHQ (SEQ ID NO: 162), ATVHQ(SEQ ID NO: 163), STVYQ (SEQ ID NO: 164), TIVHQ (SEQ ID NO: 165), AIVYQ(SEQ ID NO: 166), TTVFQ (SEQ ID NO: 167), AAVFQ (SEQ ID NO: 168), GTVHQ(SEQ ID NO: 169), ASVHQ (SEQ ID NO: 170), TAVFQ (SEQ ID NO: 171), ATVFQ(SEQ ID NO: 172), AAAHQ (SEQ ID NO: 173), VVVYQ (SEQ ID NO: 174), GTVFQ(SEQ ID NO: 175), TAVHQ (SEQ ID NO: 176), ITVHQ (SEQ ID NO: 177), ITAHQ(SEQ ID NO: 178), VTVHQ (SEQ ID NO: 179); AAVHQ (SEQ ID NO: 180), GTVYQ(SEQ ID NO: 181), TTVLQ (SEQ ID NO: 182), TTTHQ (SEQ ID NO: 183), orTTDYQ (SEQ ID NO: 184).
 152. The CDR3 scaffold of claim 142, wherein theCDR3 scaffold comprises a CX¹X²X³X⁴X⁵ motif.
 153. The CDR3 scaffold ofclaim 152, wherein the CX¹X²X³X⁴X⁵ motif in the CDR3 scaffold is CTTVHQ(SEQ ID NO: 185), CTSVHQ (SEQ ID NO: 186), CSSVTQ (SEQ ID NO: 187),CSTVHQ (SEQ ID NO: 188), CATVRQ (SEQ ID NO: 189), CTTVYQ (SEQ ID NO:190), CSPVHQ (SEQ ID NO: 191), CATVYQ (SEQ ID NO: 192), CTAVYQ (SEQ IDNO: 193), CTNVHQ (SEQ ID NO: 194), CATVHQ (SEQ ID NO: 195), CSTVYQ (SEQID NO: 196), CTIVHQ (SEQ ID NO: 197), CAIVYQ (SEQ ID NO: 198), CTTVFQ(SEQ ID NO: 199), CAAVFQ (SEQ ID NO: 200), CGTVHQ (SEQ ID NO: 201),CASVHQ (SEQ ID NO: 202), CTAVFQ (SEQ ID NO: 203), CATVFQ (SEQ ID NO:204), CAAAHQ (SEQ ID NO: 205), CVVVYQ (SEQ ID NO: 206), CGTVFQ (SEQ IDNO: 207), CTAVHQ (SEQ ID NO: 208), CITVHQ (SEQ ID NO: 209), CITAHQ (SEQID NO: 210), CVTVHQ (SEQ ID NO: 211); CAAVHQ (SEQ ID NO: 212), CGTVYQ(SEQ ID NO: 213), CTTVLQ (SEQ ID NO: 214), CTTTHQ (SEQ ID NO: 215), orCTTDYQ (SEQ ID NO: 216).
 154. The CDR3 scaffold of claim 142, whereinthe CDR3 scaffold comprises a (X^(a)X^(b))_(z) motif, wherein X^(a) isany amino acid residue, X^(b) is an aromatic amino acid selected fromthe group consisting of: tyrosine (Y), phenylalanine (F), tryptophan(W), and histidine (H), and wherein z is 1-4.
 155. The CDR3 scaffold ofclaim 154, wherein the (X^(a)X^(b))_(z) motif in the CDR3 scaffold isCYTYNYEF (SEQ ID NO: 217), HYTYTYDF (SEQ ID NO: 218), HYTYTYEW (SEQ IDNO: 219), KHRYTYEW (SEQ ID NO: 220), NYIYKYSF (SEQ ID NO: 221), PYIYTYQF(SEQ ID NO: 222), SFTYTYEW (SEQ ID NO: 223), SYIYIYQW (SEQ ID NO: 224),SYNYTYSW (SEQ ID NO: 225), SYSYSYEY (SEQ ID NO: 226), SYTYNYDF (SEQ IDNO: 227), SYTYNYEW (SEQ ID NO: 228), SYTYNYQF (SEQ ID NO: 229), SYVWTHNF(SEQ ID NO: 230), TYKYVYEW (SEQ ID NO: 231), TYTYTYEF (SEQ ID NO: 232),TYTYTYEW (SEQ ID NO: 233), VFTYTYEF (SEQ ID NO: 234), AYTYEW (SEQ ID NO:235), DYIYTY (SEQ ID NO: 236), IHSYEF (SEQ ID NO: 237), SFTYEF (SEQ IDNO: 238), SHSYEF (SEQ ID NO: 239), THTYEF (SEQ ID NO: 240), TWTYEF (SEQID NO: 241), TYNYEW (SEQ ID NO: 242), TYSYEF (SEQ ID NO: 243), TYSYEH(SEQ ID NO: 244), TYTYDF (SEQ ID NO: 245), TYTYEF (SEQ ID NO: 246),TYTYEW (SEQ ID NO: 247), AYEF (SEQ ID NO: 248), AYSF (SEQ ID NO: 249),AYSY (SEQ ID NO: 250), CYSF (SEQ ID NO: 251), DYTY (SEQ ID NO: 252),KYEH (SEQ ID NO: 253), KYEW (SEQ ID NO: 254), MYEF (SEQ ID NO: 255),NWIY (SEQ ID NO: 256), NYDY (SEQ ID NO: 257), NYQW (SEQ ID NO: 258),NYSF (SEQ ID NO: 259), PYEW (SEQ ID NO: 260), RYNW (SEQ ID NO: 261),RYTY (SEQ ID NO: 262), SYEF (SEQ ID NO: 263), SYEH (SEQ ID NO: 264),SYEW (SEQ ID NO: 265), SYKW (SEQ ID NO: 266), SYTY (SEQ ID NO: 267),TYDF (SEQ ID NO: 268), TYEF (SEQ ID NO: 269), TYEW (SEQ ID NO: 270),TYQW (SEQ ID NO: 271), TYTY (SEQ ID NO: 272), or VYEW (SEQ ID NO: 273).156. The CDR3 scaffold of claim 154, wherein the (X^(a)X^(b))_(z) motifin the CDR3 scaffold is YXYXYX.
 157. The CDR3 scaffold of claim 142,wherein the CDR3 scaffold comprises a X¹X²X³X⁴X⁵X_(n) motif, wherein X¹is threonine (T), glycine (G), alanine (A), serine (S), or valine (V),wherein X² is serine (S), threonine (T), proline (P), isoleucine (I),alanine (A), valine (V), or asparagine (N), wherein X³ is valine (V),alanine (A), threonine (T), or aspartic acid (D), wherein X⁴ ishistidine (H), threonine (T), arginine (R), tyrosine (Y), phenylalanine(F), or leucine (L), and wherein X⁵ is glutamine (Q), and wherein n is27-54.
 158. The CDR3 scaffold of claim 142, wherein the CDR3 scaffoldcomprises X_(n)(X^(a)X^(b))_(z) motif, wherein X^(a) is any amino acidresidue, X^(b) is an aromatic amino acid selected from the groupconsisting of: tyrosine (Y), phenylalanine (F), tryptophan (W), andhistidine (H), wherein n is 27-54, and wherein z is 1-4.
 159. The CDR3scaffold of claim 142, wherein the CDR3 scaffold comprises aX¹X²X³X⁴X⁵X_(n)(X^(a)X^(b))_(z) motif, wherein X₁ is threonine (T),glycine (G), alanine (A), serine (S), or valine (V), wherein X₂ isserine (S), threonine (T), proline (P), isoleucine (I), alanine (A),valine (V), or asparagine (N), wherein X₃ is valine (V), alanine (A),threonine (T), or aspartic acid (D), wherein X₄ is histidine (H),threonine (T), arginine (R), tyrosine (Y), phenylalanine (F), or leucine(L), wherein X₅ is glutamine (Q), X^(a) is any amino acid residue, X^(b)is an aromatic amino acid selected from the group consisting of:tyrosine (Y), phenylalanine (F), tryptophan (W), and histidine (H),wherein n is 27-54, and wherein z is 1-4.
 160. The CDR3 scaffold ofclaim 159, wherein the X¹X²X³X⁴X⁵ motif in the CDR3 scaffold is TTVHQ(SEQ ID NO: 153) or TSVHQ (SEQ ID NO: 154), and wherein the(X^(a)X^(b))_(z) motif is YXYXYX.
 161. The CDR3 scaffold of claim 142,wherein the CDR3 scaffold comprises: a CX¹X²X³X⁴X⁵ motif, wherein X¹ isthreonine (T), glycine (G), alanine (A), serine (S), or valine (V),wherein X² is serine (S), threonine (T), proline (P), isoleucine (I),alanine (A), valine (V), or asparagine (N), wherein X³ is valine (V),alanine (A), threonine (T), or aspartic acid (D), wherein X⁴ ishistidine (H), threonine (T), arginine (R), tyrosine (Y), phenylalanine(F), or leucine (L), and wherein X⁵ is glutamine (Q), a cysteine motifselected from the group consisting of: CX₁₀CX₅CX₅CXCX₇C (SEQ ID NO: 41),CX₁₀CX₆CX₅CXCX₁₅C (SEQ ID NO: 42), CX₁₁CXCX₅C (SEQ ID NO: 43),CX₁₁CX₅CX₅CXCX₇C (SEQ ID NO: 44), CX₁₀CX₆CX₅CXCX₁₃C (SEQ ID NO: 45),CX₁₀CX₅CXCX₄CX₈C (SEQ ID NO: 46), CX₁₀CX₆CX₆CXCX₇C (SEQ ID NO: 47),CX₁₀CX₄CX₇CXCX₈C (SEQ ID NO: 48), CX₁₀CX₄CX₇CXCX₇C (SEQ ID NO: 49),CX₁₃CX₈CX₈C (SEQ ID NO: 50), CX₁₀CX₆CX₅CXCX₇C (SEQ ID NO: 51),CX₁₀CX₅CX₅C (SEQ ID NO: 52), CX₁₀CX₅CX₆CXCX₇C (SEQ ID NO: 53),CX₁₀CX₆CX₅CX₇CX₉C (SEQ ID NO: 54), CX₉CX₇CX₅CXCX₇C (SEQ ID NO: 55),CX₁₀CX₆CX₅CXCX₉C (SEQ ID NO: 56), CX₁₀CXCX₄CX₅CX₁₁C (SEQ ID NO: 57),CX₇CX₃CX₆CX₅CXCX₅CX₁₀C (SEQ ID NO: 58), CX₁₀CXCX₄CX₅CXCX₂CX₃C (SEQ IDNO: 59), CX₁₆CX₅CXC (SEQ ID NO: 60), CX₆CX₄CXCX₄CX₅C (SEQ ID NO: 61),CX₁₁CX₄CX₅CX₆CX₃C (SEQ ID NO: 62), CX₈CX₂CX₆CX₅C (SEQ ID NO: 63),CX₁₀CX₅CX₅CXCX₁₀C (SEQ ID NO: 64), CX₁₀CXCX₆CX₄CXC (SEQ ID NO: 65),CX₁₀CX₅CX₅CXCX₂C (SEQ ID NO: 66), CX₁₄CX₂CX₃CXCXC (SEQ ID NO: 67),CX₁₅CX₅CXC (SEQ ID NO: 68), CX₄CX₆CX₉CX₂CX₁₁C (SEQ ID NO: 69),CX₆CX₄CX₅CX₅CX₁₂C (SEQ ID NO: 70), CX₇CX₃CXCXCX₄CX₅CX₉C (SEQ ID NO: 71),CX₁₀CX₆CX₅C (SEQ ID NO: 72), CX₇CX₃CX₅CX₅CX₉C (SEQ ID NO: 73),CX₇CX₅CXCX₂C (SEQ ID NO: 74), CX₁₀CXCX₆C (SEQ ID NO: 75),CX₁₀CX₃CX₃CX₅CX₇CXCX₆C (SEQ ID NO: 76), CX₁₀CX₄CX₅CX₁₂CX₂C (SEQ ID NO:77), CX₁₂CX₄CX₅CXCXCX₉CX₃C (SEQ ID NO: 78), CX₁₂CX₄CX₅CX₁₂CX₂C (SEQ IDNO: 79), CX₁₀CX₆CX₅CXCX₁₁C (SEQ ID NO: 80), CX₁₆CX₅CXCXCX₁₄C (SEQ ID NO:81), CX₁₀CX₅CXCX₈CX₆C (SEQ ID NO: 82), CX₁₂CX₄CX₅CX₈CX₂C (SEQ ID NO:83), CX₁₂CX₅CX₅CXCX₈C (SEQ ID NO: 84), CX₁₀CX₆CX₅CXCX₄CXCX₉C (SEQ ID NO:85), CX₁₁CX₄CX₅CX₈CX₂C (SEQ ID NO: 86), CX₁₀CX₆CX₅CX₈CX₂C (SEQ ID NO:87), CX₁₀CX₆CX₅CXCX₈C (SEQ ID NO: 88), CX₁₀CX₆CX₅CXCX₃CX₈CX₂C (SEQ IDNO: 89), CX₁₀CX₆CX₅CX₃CX₈C (SEQ ID NO: 90), CX₁₀CX₆CX₅CXCX₂CX₆CX₅C (SEQID NO: 91), CX₇CX₆CX₃CX₃CX₉C (SEQ ID NO: 92), CX₉CX₈CX₅CX₆CX₅C (SEQ IDNO: 93), CX₁₀CX₂CX₂CX₇CXCX₁₁CX₅C (SEQ ID NO: 94), andCX₁₀CX₆CX₅CXCX₂CX₈CX₄C (SEQ ID NO: 95), and a (X^(a)X^(b))_(z) motif,wherein X^(a) is any amino acid residue, X^(b) is an aromatic amino acidselected from the group consisting of: tyrosine (Y), phenylalanine (F),tryptophan (W), and histidine (H), and wherein z is 1-4.
 162. The CDR3scaffold of claim 142, wherein the CDR3 scaffold comprises: aCX¹X²X³X⁴X⁵ motif, wherein X¹ is threonine (T), glycine (G), alanine(A), serine (S), or valine (V), wherein X² is serine (S), threonine (T),proline (P), isoleucine (I), alanine (A), valine (V), or asparagine (N),wherein X³ is valine (V), alanine (A), threonine (T), or aspartic acid(D), wherein X⁴ is histidine (H), threonine (T), arginine (R), tyrosine(Y), phenylalanine (F), or leucine (L), and wherein X⁵ is glutamine (Q);a cysteine motif selected from the group consisting of: wherein thecysteine motif is selected from the group consisting of:CCX₃CXCX₃CX₂CCXCX₅CX₉CX₅CXC (SEQ ID NO: 96), CX₆CX₂CX₅CX₄CCXCX₄CX₆CXC(SEQ ID NO: 97), CX₇CXCX₅CX₄CCCX₄CX₆CXC (SEQ ID NO: 98),CX₉CX₃CXCX₂CXCCCX₆CX₄C (SEQ ID NO: 99), CX₅CX₃CXCX₄CX₄CCX₁₀CX₂CC (SEQ IDNO: 100), CX₅CXCX₁CXCX₃CCX₃CX₄CX₁₀C (SEQ ID NO: 101),CX₉CCCX₃CX₄CCCX₅CX₆C (SEQ ID NO: 102), CCX₈CX₅CX₄CX₃CX₄CCXCX₁C (SEQ IDNO: 103), CCX₆CCX₅CCCX₄CX₄CX₁₂C (SEQ ID NO: 104),CX₆CX₂CX₃CCCX₄CX₅CX₃CX₃C (SEQ ID NO: 105), CX₃CX₅CX₆CX₄CCXCX₅CX₄CXC (SEQID NO: 106), CX₄CX₄CCX₄CX₄CXCX₁₁CX₂CXC (SEQ ID NO: 107),CX₅CX₂CCX₅CX₄CCX₃CCX₇C (SEQ ID NO: 108), CX₅CX₅CX₃CX₂CXCCX₄CX₇CXC (SEQID NO: 109), CX₃CX₇CX₃CX₄CCXCX₂CX₅CX₂C (SEQ ID NO: 110),CX₉CX₃CXCX₄CCX₅CCCX₆C (SEQ ID NO: 111), CX₉CX₃CXCX₂CXCCX₆CX₃CX₃C (SEQ IDNO: 112), CX₈CCXCX₃CCX₃CXCX₃CX₄C (SEQ ID NO: 113),CX₉CCX₄CX₂CXCCXCX₄CX₃C (SEQ ID NO: 114), CX₁₀CXCX₃CX₂CXCCX₄CX₅CXC (SEQID NO: 115), CX₉CXCX₃CX₂CXCCX₄CX₅CXC (SEQ ID NO: 116),CX₆CCXCX₅CX₄CCXCX₅CX₂C (SEQ ID NO: 117), CX₆CCXCX₃CXCCX₃CX₄CC (SEQ IDNO: 118), CX₆CCXCX₃CXCX₂CXCX₄CX₈C (SEQ ID NO: 119),CX₄CX₂CCX₃CXCX₄CCX₂CX₃C (SEQ ID NO: 120), CX₃CX₅CX₃CCCX₄CX₉C (SEQ ID NO:121), CCX₉CX₃CXCCX₃CX₅C (SEQ ID NO: 122), CX₉CX₂CX₃CX₄CCX₄CX₅C (SEQ IDNO: 123), CX₉CX₇CX₄CCXCX₇CX₃C (SEQ ID NO: 124), CX₉CX₃CCCX₁₀CX₂CX₃C (SEQID NO: 125), CX₃CX₅CX₅CX₄CCX₁₀CX₆C (SEQ ID NO: 126), CX₉CX₅CX₄CCXCX₅CX₄C(SEQ ID NO: 127), CX₇CXCX₆CX₄CCCX₁₀C (SEQ ID NO: 128),CX₈CX₂CX₄CCX₄CX₃CX₃C (SEQ ID NO: 129), CX₇CX₅CXCX₄CCX₇CX₄C (SEQ ID NO:130), CX₁₁CX₃CX₄CCCX₈CX₂C (SEQ ID NO: 131), CX₂CX₃CX₄CCX₄CX₅CX₁₅C (SEQID NO: 132), CX₉CX₅CX₄CCX₇C (SEQ ID NO: 133), CX₉CX₇CX₃CX₂CX₆C (SEQ IDNO: 134), CX₉CX₅CX₄CCX₁₄C (SEQ ID NO: 135), CX₉CX₅CX₄CCX₈C (SEQ ID NO:136), CX₉CX₆CX₄CCXC (SEQ ID NO: 137), CX₅CCX₇CX₄CX₁₂ (SEQ ID NO: 138),CX₁₀CX₃CX₄CCX₄C (SEQ ID NO: 139), CX₉CX₄CCX₅CX₄C (SEQ ID NO: 140),CX₁₀CX₃CX₄CX₇CXC (SEQ ID NO: 141), CX₇CX₇CX₂CX₂CX₃C (SEQ ID NO: 142),CX₉CX₄CX₄CCX₆C (SEQ ID NO: 143), CX₇CXCX₃CXCX₆C (SEQ ID NO: 144),CX₇CXCX₄CXCX₄C (SEQ ID NO: 145), CX₉CX₅CX₄C (SEQ ID NO: 146), CX₃CX₆CX₈C(SEQ ID NO: 147), CX₁₀CXCX₄C (SEQ ID NO: 148), CX₁₀CCX₄C (SEQ ID NO:149), CX₁₅C (SEQ ID NO: 150), CX₁₀C (SEQ ID NO: 151), and CX₉C (SEQ IDNO: 152); and a (X^(a)X^(b))_(z) motif, wherein X^(a) is any amino acidresidue, X^(b) is an aromatic amino acid selected from the groupconsisting of: tyrosine (Y), phenylalanine (F), tryptophan (W), andhistidine (H), and wherein z is 1-4.
 163. The CDR3 scaffold of claim142, wherein the CDR3 scaffold comprises SEQ ID NO: 40 or a derivativethereof.
 164. The CDR3 scaffold of claim 142, wherein the CDR3 scaffoldcomprises amino acid residues 3-6 of any of one SEQ ID NO: 1-4.
 165. TheCDR3 scaffold of claim 142, wherein the CDR3 scaffold comprises anon-human DH or a derivative thereof.
 166. The CDR3 scaffold of claim165, wherein the non-human DH is SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO:7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, or SEQ IDNO: 12
 167. The CDR3 scaffold of claim 142, wherein the CDR3 scaffoldcomprises a JH sequence or a derivative thereof.
 168. The CDR3 scaffoldof claim 167, wherein the JH sequence is SEQ ID NO: 13, SEQ ID NO: 14,SEQ ID NO: 15, SEQ ID NO: 16, or SEQ ID NO:
 17. 169. The CDR3 scaffoldof claim 142, wherein the CDR3 scaffold comprises: a non-human VHsequence or a derivative thereof; a non-human DH sequence or aderivative thereof; and/or a JH sequence or derivative thereof.
 170. TheCDR3 scaffold of claim 169, wherein the CDR3 scaffold comprises anadditional amino acid sequence comprising two to six amino acid residuesor more positioned between the VH sequence and the DH sequence.
 171. TheCDR3 scaffold of claim 170, wherein the additional amino acid sequenceis selected from the group consisting of: IR, IF, SEQ ID NO: 18, SEQ IDNO: 19, SEQ ID NO: 20 or SEQ ID NO:
 21. 172. The CDR3 scaffold of claim142, wherein the CDR3 scaffold comprises a sequence derived from orbased on SEQ ID NO: 22, SEQ ID NO: 23, SEQ ID NO: 24, SEQ ID NO: 25, SEQID NO: 26, SEQ ID NO: 27, or SEQ ID NO:
 28. 173. The CDR3 scaffold ofclaim 142, wherein the CDR3 scaffold is a ruminant CDR3 scaffold. 174.The CDR3 scaffold of claim 173, wherein the ruminant is a cow.
 175. Alibrary comprising the CDR3 scaffold of any one of claims 142-174. 176.A polynucleotide encoding the CDR3 scaffold of any one of claims142-174.
 177. A vector comprising the polynucleotide of claim
 176. 178.A host cell comprising the vector of claim
 177. 179. The host cell ofclaim 178, wherein the cell is a bacteria, virus, or bacteriophage.